Package org.apache.commons.lang3

Class StringUtils

  • public class StringUtils
extends java.lang.Object

    Operations on String that are null safe.

    • IsEmpty/IsBlank - checks if a String contains text
    • Trim/Strip - removes leading and trailing whitespace
    • Equals/Compare - compares two strings in a null-safe manner
    • startsWith - check if a String starts with a prefix in a null-safe manner
    • endsWith - check if a String ends with a suffix in a null-safe manner
    • IndexOf/LastIndexOf/Contains - null-safe index-of checks
    • IndexOfAny/LastIndexOfAny/IndexOfAnyBut/LastIndexOfAnyBut - index-of any of a set of Strings
    • ContainsOnly/ContainsNone/ContainsAny - checks if String contains only/none/any of these characters
    • Substring/Left/Right/Mid - null-safe substring extractions
    • SubstringBefore/SubstringAfter/SubstringBetween - substring extraction relative to other strings
    • Split/Join - splits a String into an array of substrings and vice versa
    • Remove/Delete - removes part of a String
    • Replace/Overlay - Searches a String and replaces one String with another
    • Chomp/Chop - removes the last part of a String
    • AppendIfMissing - appends a suffix to the end of the String if not present
    • PrependIfMissing - prepends a prefix to the start of the String if not present
    • LeftPad/RightPad/Center/Repeat - pads a String
    • UpperCase/LowerCase/SwapCase/Capitalize/Uncapitalize - changes the case of a String
    • CountMatches - counts the number of occurrences of one String in another
    • IsAlpha/IsNumeric/IsWhitespace/IsAsciiPrintable - checks the characters in a String
    • DefaultString - protects against a null input String
    • Rotate - rotate (circular shift) a String
    • Reverse/ReverseDelimited - reverses a String
    • Abbreviate - abbreviates a string using ellipses or another given String
    • Difference - compares Strings and reports on their differences
    • LevenshteinDistance - the number of changes needed to change one String into another

    The StringUtils class defines certain words related to String handling.

    • null - null
    • empty - a zero-length string ("")
    • space - the space character (' ', char 32)
    • whitespace - the characters defined by Character.isWhitespace(char)
    • trim - the characters <= 32 as in String.trim()

    StringUtils handles null input Strings quietly. That is to say that a null input will return null. Where a boolean or int is being returned details vary by method.

    A side effect of the null handling is that a NullPointerException should be considered a bug in StringUtils.

    Methods in this class include sample code in their Javadoc comments to explain their operation. The symbol * is used to indicate any input including null.

    #ThreadSafe#

    Since:
    1.0
    See Also:
    String

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String CR
      A String for carriage return CR ("\r").
      static java.lang.String EMPTY
      The empty String "".
      static int INDEX_NOT_FOUND
      Represents a failed index search.
      static java.lang.String LF
      A String for linefeed LF ("\n").
      static java.lang.String SPACE
      A String for a space character.

    • Constructor Summary

      Constructors 
      Constructor Description
      StringUtils()
      StringUtils instances should NOT be constructed in standard programming.

    • Method Summary

      All Methods Static Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      static java.lang.String abbreviate​(java.lang.String str, int maxWidth)
      Abbreviates a String using ellipses.
      static java.lang.String abbreviate​(java.lang.String str, int offset, int maxWidth)
      Abbreviates a String using ellipses.
      static java.lang.String abbreviate​(java.lang.String str, java.lang.String abbrevMarker, int maxWidth)
      Abbreviates a String using another given String as replacement marker.
      static java.lang.String abbreviate​(java.lang.String str, java.lang.String abbrevMarker, int offset, int maxWidth)
      Abbreviates a String using a given replacement marker.
      static java.lang.String abbreviateMiddle​(java.lang.String str, java.lang.String middle, int length)
      Abbreviates a String to the length passed, replacing the middle characters with the supplied replacement String.
      static java.lang.String capitalize​(java.lang.String str)
      Capitalizes a String changing the first character to title case as per Character.toTitleCase(int).
      static java.lang.String center​(java.lang.String str, int size)
      Centers a String in a larger String of size size using the space character (' ').
      static java.lang.String center​(java.lang.String str, int size, char padChar)
      Centers a String in a larger String of size size.
      static java.lang.String center​(java.lang.String str, int size, java.lang.String padStr)
      Centers a String in a larger String of size size.
      static java.lang.String chomp​(java.lang.String str)
      Removes one newline from end of a String if it's there, otherwise leave it alone.
      static java.lang.String chomp​(java.lang.String str, java.lang.String separator)
      Deprecated.
      This feature will be removed in Lang 4.0, use removeEnd(String, String) instead
      static java.lang.String chop​(java.lang.String str)
      Remove the last character from a String.
      static int compare​(java.lang.String str1, java.lang.String str2)
      Compare two Strings lexicographically, as per String.compareTo(String), returning :
      static int compare​(java.lang.String str1, java.lang.String str2, boolean nullIsLess)
      Compare two Strings lexicographically, as per String.compareTo(String), returning :
      static int compareIgnoreCase​(java.lang.String str1, java.lang.String str2)
      Compare two Strings lexicographically, ignoring case differences, as per String.compareToIgnoreCase(String), returning :
      static int compareIgnoreCase​(java.lang.String str1, java.lang.String str2, boolean nullIsLess)
      Compare two Strings lexicographically, ignoring case differences, as per String.compareToIgnoreCase(String), returning :
      static boolean contains​(java.lang.CharSequence seq, int searchChar)
      Checks if CharSequence contains a search character, handling null.
      static boolean contains​(java.lang.CharSequence seq, java.lang.CharSequence searchSeq)
      Checks if CharSequence contains a search CharSequence, handling null.
      static boolean containsAny​(java.lang.CharSequence cs, char... searchChars)
      Checks if the CharSequence contains any character in the given set of characters.
      static boolean containsAny​(java.lang.CharSequence cs, java.lang.CharSequence searchChars)
      Checks if the CharSequence contains any character in the given set of characters.
      static boolean containsAny​(java.lang.CharSequence cs, java.lang.CharSequence... searchCharSequences)
      Checks if the CharSequence contains any of the CharSequences in the given array.
      static boolean containsAnyIgnoreCase​(java.lang.CharSequence cs, java.lang.CharSequence... searchCharSequences)
      Checks if the CharSequence contains any of the CharSequences in the given array, ignoring case.
      static boolean containsIgnoreCase​(java.lang.CharSequence str, java.lang.CharSequence searchStr)
      Checks if CharSequence contains a search CharSequence irrespective of case, handling null.
      static boolean containsNone​(java.lang.CharSequence cs, char... searchChars)
      Checks that the CharSequence does not contain certain characters.
      static boolean containsNone​(java.lang.CharSequence cs, java.lang.String invalidChars)
      Checks that the CharSequence does not contain certain characters.
      static boolean containsOnly​(java.lang.CharSequence cs, char... valid)
      Checks if the CharSequence contains only certain characters.
      static boolean containsOnly​(java.lang.CharSequence cs, java.lang.String validChars)
      Checks if the CharSequence contains only certain characters.
      static boolean containsWhitespace​(java.lang.CharSequence seq)
      Check whether the given CharSequence contains any whitespace characters.
      static int countMatches​(java.lang.CharSequence str, char ch)
      Counts how many times the char appears in the given string.
      static int countMatches​(java.lang.CharSequence str, java.lang.CharSequence sub)
      Counts how many times the substring appears in the larger string.
      static <T extends java.lang.CharSequence>
      T      		 defaultIfBlank​(T str, T defaultStr)
      Returns either the passed in CharSequence, or if the CharSequence is whitespace, empty ("") or null, the value of defaultStr.
      static <T extends java.lang.CharSequence>
      T      		 defaultIfEmpty​(T str, T defaultStr)
      Returns either the passed in CharSequence, or if the CharSequence is empty or null, the value of defaultStr.
      static java.lang.String defaultString​(java.lang.String str)
      Returns either the passed in String, or if the String is null, an empty String ("").
      static java.lang.String defaultString​(java.lang.String str, java.lang.String defaultStr)
      Returns either the passed in String, or if the String is null, the value of defaultStr.
      static java.lang.String deleteWhitespace​(java.lang.String str)
      Deletes all whitespaces from a String as defined by Character.isWhitespace(char).
      static java.lang.String difference​(java.lang.String str1, java.lang.String str2)
      Compares two Strings, and returns the portion where they differ.
      static boolean endsWith​(java.lang.CharSequence str, java.lang.CharSequence suffix)
      Check if a CharSequence ends with a specified suffix.
      static boolean endsWithAny​(java.lang.CharSequence sequence, java.lang.CharSequence... searchStrings)
      Check if a CharSequence ends with any of the provided case-sensitive suffixes.
      static boolean endsWithIgnoreCase​(java.lang.CharSequence str, java.lang.CharSequence suffix)
      Case insensitive check if a CharSequence ends with a specified suffix.
      static boolean equals​(java.lang.CharSequence cs1, java.lang.CharSequence cs2)
      Compares two CharSequences, returning true if they represent equal sequences of characters.
      static boolean equalsAny​(java.lang.CharSequence string, java.lang.CharSequence... searchStrings)
      Compares given string to a CharSequences vararg of searchStrings, returning true if the string is equal to any of the searchStrings.
      static boolean equalsAnyIgnoreCase​(java.lang.CharSequence string, java.lang.CharSequence... searchStrings)
      Compares given string to a CharSequences vararg of searchStrings, returning true if the string is equal to any of the searchStrings, ignoring case.
      static boolean equalsIgnoreCase​(java.lang.CharSequence cs1, java.lang.CharSequence cs2)
      Compares two CharSequences, returning true if they represent equal sequences of characters, ignoring case.
      static <T extends java.lang.CharSequence>
      T      		 firstNonBlank​(T... values)
      Returns the first value in the array which is not empty (""), null or whitespace only.
      static <T extends java.lang.CharSequence>
      T      		 firstNonEmpty​(T... values)
      Returns the first value in the array which is not empty.
      static byte[] getBytes​(java.lang.String string, java.lang.String charset)
      Calls String.getBytes(String) in a null-safe manner.
      static byte[] getBytes​(java.lang.String string, java.nio.charset.Charset charset)
      Calls String.getBytes(Charset) in a null-safe manner.
      static java.lang.String getCommonPrefix​(java.lang.String... strs)
      Compares all Strings in an array and returns the initial sequence of characters that is common to all of them.
      static java.lang.String getDigits​(java.lang.String str)
      Checks if a String str contains Unicode digits, if yes then concatenate all the digits in str and return it as a String.
      static int getFuzzyDistance​(java.lang.CharSequence term, java.lang.CharSequence query, java.util.Locale locale)
      Deprecated.
      as of 3.6, use commons-text FuzzyScore instead
      static <T extends java.lang.CharSequence>
      T      		 getIfBlank​(T str, java.util.function.Supplier<T> defaultSupplier)
      Returns either the passed in CharSequence, or if the CharSequence is whitespace, empty ("") or null, the value supplied by defaultStrSupplier.
      static <T extends java.lang.CharSequence>
      T      		 getIfEmpty​(T str, java.util.function.Supplier<T> defaultSupplier)
      Returns either the passed in CharSequence, or if the CharSequence is empty or null, the value supplied by defaultStrSupplier.
      static double getJaroWinklerDistance​(java.lang.CharSequence first, java.lang.CharSequence second)
      Deprecated.
      as of 3.6, use commons-text JaroWinklerDistance instead
      static int getLevenshteinDistance​(java.lang.CharSequence s, java.lang.CharSequence t)
      Deprecated.
      as of 3.6, use commons-text LevenshteinDistance instead
      static int getLevenshteinDistance​(java.lang.CharSequence s, java.lang.CharSequence t, int threshold)
      Deprecated.
      as of 3.6, use commons-text LevenshteinDistance instead
      static int indexOf​(java.lang.CharSequence seq, int searchChar)
      Returns the index within seq of the first occurrence of the specified character.
      static int indexOf​(java.lang.CharSequence seq, int searchChar, int startPos)
      Returns the index within seq of the first occurrence of the specified character, starting the search at the specified index.
      static int indexOf​(java.lang.CharSequence seq, java.lang.CharSequence searchSeq)
      Finds the first index within a CharSequence, handling null.
      static int indexOf​(java.lang.CharSequence seq, java.lang.CharSequence searchSeq, int startPos)
      Finds the first index within a CharSequence, handling null.
      static int indexOfAny​(java.lang.CharSequence cs, char... searchChars)
      Search a CharSequence to find the first index of any character in the given set of characters.
      static int indexOfAny​(java.lang.CharSequence str, java.lang.CharSequence... searchStrs)
      Find the first index of any of a set of potential substrings.
      static int indexOfAny​(java.lang.CharSequence cs, java.lang.String searchChars)
      Search a CharSequence to find the first index of any character in the given set of characters.
      static int indexOfAnyBut​(java.lang.CharSequence cs, char... searchChars)
      Searches a CharSequence to find the first index of any character not in the given set of characters.
      static int indexOfAnyBut​(java.lang.CharSequence seq, java.lang.CharSequence searchChars)
      Search a CharSequence to find the first index of any character not in the given set of characters.
      static int indexOfDifference​(java.lang.CharSequence... css)
      Compares all CharSequences in an array and returns the index at which the CharSequences begin to differ.
      static int indexOfDifference​(java.lang.CharSequence cs1, java.lang.CharSequence cs2)
      Compares two CharSequences, and returns the index at which the CharSequences begin to differ.
      static int indexOfIgnoreCase​(java.lang.CharSequence str, java.lang.CharSequence searchStr)
      Case in-sensitive find of the first index within a CharSequence.
      static int indexOfIgnoreCase​(java.lang.CharSequence str, java.lang.CharSequence searchStr, int startPos)
      Case in-sensitive find of the first index within a CharSequence from the specified position.
      static boolean isAllBlank​(java.lang.CharSequence... css)
      Checks if all of the CharSequences are empty (""), null or whitespace only.
      static boolean isAllEmpty​(java.lang.CharSequence... css)
      Checks if all of the CharSequences are empty ("") or null.
      static boolean isAllLowerCase​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only lowercase characters.
      static boolean isAllUpperCase​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only uppercase characters.
      static boolean isAlpha​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only Unicode letters.
      static boolean isAlphanumeric​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only Unicode letters or digits.
      static boolean isAlphanumericSpace​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only Unicode letters, digits or space (' ').
      static boolean isAlphaSpace​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only Unicode letters and space (' ').
      static boolean isAnyBlank​(java.lang.CharSequence... css)
      Checks if any of the CharSequences are empty ("") or null or whitespace only.
      static boolean isAnyEmpty​(java.lang.CharSequence... css)
      Checks if any of the CharSequences are empty ("") or null.
      static boolean isAsciiPrintable​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only ASCII printable characters.
      static boolean isBlank​(java.lang.CharSequence cs)
      Checks if a CharSequence is empty (""), null or whitespace only.
      static boolean isEmpty​(java.lang.CharSequence cs)
      Checks if a CharSequence is empty ("") or null.
      static boolean isMixedCase​(java.lang.CharSequence cs)
      Checks if the CharSequence contains mixed casing of both uppercase and lowercase characters.
      static boolean isNoneBlank​(java.lang.CharSequence... css)
      Checks if none of the CharSequences are empty (""), null or whitespace only.
      static boolean isNoneEmpty​(java.lang.CharSequence... css)
      Checks if none of the CharSequences are empty ("") or null.
      static boolean isNotBlank​(java.lang.CharSequence cs)
      Checks if a CharSequence is not empty (""), not null and not whitespace only.
      static boolean isNotEmpty​(java.lang.CharSequence cs)
      Checks if a CharSequence is not empty ("") and not null.
      static boolean isNumeric​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only Unicode digits.
      static boolean isNumericSpace​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only Unicode digits or space (' ').
      static boolean isWhitespace​(java.lang.CharSequence cs)
      Checks if the CharSequence contains only whitespace.
      static java.lang.String join​(boolean[] array, char delimiter)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(boolean[] array, char delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(byte[] array, char delimiter)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(byte[] array, char delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(char[] array, char delimiter)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(char[] array, char delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(double[] array, char delimiter)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(double[] array, char delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(float[] array, char delimiter)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(float[] array, char delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(int[] array, char separator)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(int[] array, char delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(long[] array, char separator)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(long[] array, char delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(short[] array, char delimiter)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(short[] array, char delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(java.lang.Iterable<?> iterable, char separator)
      Joins the elements of the provided Iterable into a single String containing the provided elements.
      static java.lang.String join​(java.lang.Iterable<?> iterable, java.lang.String separator)
      Joins the elements of the provided Iterable into a single String containing the provided elements.
      static java.lang.String join​(java.lang.Object[] array, char delimiter)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(java.lang.Object[] array, char delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(java.lang.Object[] array, java.lang.String delimiter)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(java.lang.Object[] array, java.lang.String delimiter, int startIndex, int endIndex)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String join​(java.util.Iterator<?> iterator, char separator)
      Joins the elements of the provided Iterator into a single String containing the provided elements.
      static java.lang.String join​(java.util.Iterator<?> iterator, java.lang.String separator)
      Joins the elements of the provided Iterator into a single String containing the provided elements.
      static java.lang.String join​(java.util.List<?> list, char separator, int startIndex, int endIndex)
      Joins the elements of the provided List into a single String containing the provided list of elements.
      static java.lang.String join​(java.util.List<?> list, java.lang.String separator, int startIndex, int endIndex)
      Joins the elements of the provided List into a single String containing the provided list of elements.
      static <T> java.lang.String join​(T... elements)
      Joins the elements of the provided array into a single String containing the provided list of elements.
      static java.lang.String joinWith​(java.lang.String delimiter, java.lang.Object... array)
      Joins the elements of the provided varargs into a single String containing the provided elements.
      static int lastIndexOf​(java.lang.CharSequence seq, int searchChar)
      Returns the index within seq of the last occurrence of the specified character.
      static int lastIndexOf​(java.lang.CharSequence seq, int searchChar, int startPos)
      Returns the index within seq of the last occurrence of the specified character, searching backward starting at the specified index.
      static int lastIndexOf​(java.lang.CharSequence seq, java.lang.CharSequence searchSeq)
      Finds the last index within a CharSequence, handling null.
      static int lastIndexOf​(java.lang.CharSequence seq, java.lang.CharSequence searchSeq, int startPos)
      Finds the last index within a CharSequence, handling null.
      static int lastIndexOfAny​(java.lang.CharSequence str, java.lang.CharSequence... searchStrs)
      Find the latest index of any substring in a set of potential substrings.
      static int lastIndexOfIgnoreCase​(java.lang.CharSequence str, java.lang.CharSequence searchStr)
      Case in-sensitive find of the last index within a CharSequence.
      static int lastIndexOfIgnoreCase​(java.lang.CharSequence str, java.lang.CharSequence searchStr, int startPos)
      Case in-sensitive find of the last index within a CharSequence from the specified position.
      static int lastOrdinalIndexOf​(java.lang.CharSequence str, java.lang.CharSequence searchStr, int ordinal)
      Finds the n-th last index within a String, handling null.
      static java.lang.String left​(java.lang.String str, int len)
      Gets the leftmost len characters of a String.
      static java.lang.String leftPad​(java.lang.String str, int size)
      Left pad a String with spaces (' ').
      static java.lang.String leftPad​(java.lang.String str, int size, char padChar)
      Left pad a String with a specified character.
      static java.lang.String leftPad​(java.lang.String str, int size, java.lang.String padStr)
      Left pad a String with a specified String.
      static int length​(java.lang.CharSequence cs)
      Gets a CharSequence length or 0 if the CharSequence is null.
      static java.lang.String lowerCase​(java.lang.String str)
      Converts a String to lower case as per String.toLowerCase().
      static java.lang.String lowerCase​(java.lang.String str, java.util.Locale locale)
      Converts a String to lower case as per String.toLowerCase(Locale).
      static java.lang.String mid​(java.lang.String str, int pos, int len)
      Gets len characters from the middle of a String.
      static java.lang.String normalizeSpace​(java.lang.String str)
      Similar to http://www.w3.org/TR/xpath/#function-normalize -space
      static int ordinalIndexOf​(java.lang.CharSequence str, java.lang.CharSequence searchStr, int ordinal)
      Finds the n-th index within a CharSequence, handling null.
      static java.lang.String overlay​(java.lang.String str, java.lang.String overlay, int start, int end)
      Overlays part of a String with another String.
      static java.lang.String prependIfMissing​(java.lang.String str, java.lang.CharSequence prefix, java.lang.CharSequence... prefixes)
      Prepends the prefix to the start of the string if the string does not already start with any of the prefixes.
      static java.lang.String prependIfMissingIgnoreCase​(java.lang.String str, java.lang.CharSequence prefix, java.lang.CharSequence... prefixes)
      Prepends the prefix to the start of the string if the string does not already start, case insensitive, with any of the prefixes.
      static java.lang.String remove​(java.lang.String str, char remove)
      Removes all occurrences of a character from within the source string.
      static java.lang.String remove​(java.lang.String str, java.lang.String remove)
      Removes all occurrences of a substring from within the source string.
      static java.lang.String removeAll​(java.lang.String text, java.lang.String regex)
      Deprecated.
      Moved to RegExUtils.
      static java.lang.String removeEnd​(java.lang.String str, java.lang.String remove)
      Removes a substring only if it is at the end of a source string, otherwise returns the source string.
      static java.lang.String removeEndIgnoreCase​(java.lang.String str, java.lang.String remove)
      Case insensitive removal of a substring if it is at the end of a source string, otherwise returns the source string.
      static java.lang.String removeFirst​(java.lang.String text, java.lang.String regex)
      Deprecated.
      Moved to RegExUtils.
      static java.lang.String removeIgnoreCase​(java.lang.String str, java.lang.String remove)
      Case insensitive removal of all occurrences of a substring from within the source string.
      static java.lang.String removePattern​(java.lang.String source, java.lang.String regex)
      Deprecated.
      Moved to RegExUtils.
      static java.lang.String removeStart​(java.lang.String str, java.lang.String remove)
      Removes a substring only if it is at the beginning of a source string, otherwise returns the source string.
      static java.lang.String removeStartIgnoreCase​(java.lang.String str, java.lang.String remove)
      Case insensitive removal of a substring if it is at the beginning of a source string, otherwise returns the source string.
      static java.lang.String repeat​(char ch, int repeat)
      Returns padding using the specified delimiter repeated to a given length.
      static java.lang.String repeat​(java.lang.String str, int repeat)
      Repeat a String repeat times to form a new String.
      static java.lang.String repeat​(java.lang.String str, java.lang.String separator, int repeat)
      Repeat a String repeat times to form a new String, with a String separator injected each time.
      static java.lang.String replace​(java.lang.String text, java.lang.String searchString, java.lang.String replacement)
      Replaces all occurrences of a String within another String.
      static java.lang.String replace​(java.lang.String text, java.lang.String searchString, java.lang.String replacement, int max)
      Replaces a String with another String inside a larger String, for the first max values of the search String.
      static java.lang.String replaceAll​(java.lang.String text, java.lang.String regex, java.lang.String replacement)
      Deprecated.
      Moved to RegExUtils.
      static java.lang.String replaceChars​(java.lang.String str, char searchChar, char replaceChar)
      Replaces all occurrences of a character in a String with another.
      static java.lang.String replaceChars​(java.lang.String str, java.lang.String searchChars, java.lang.String replaceChars)
      Replaces multiple characters in a String in one go.
      static java.lang.String replaceEach​(java.lang.String text, java.lang.String[] searchList, java.lang.String[] replacementList)
      Replaces all occurrences of Strings within another String.
      static java.lang.String replaceEachRepeatedly​(java.lang.String text, java.lang.String[] searchList, java.lang.String[] replacementList)
      Replaces all occurrences of Strings within another String.
      static java.lang.String replaceFirst​(java.lang.String text, java.lang.String regex, java.lang.String replacement)
      Deprecated.
      Moved to RegExUtils.
      static java.lang.String replaceIgnoreCase​(java.lang.String text, java.lang.String searchString, java.lang.String replacement)
      Case insensitively replaces all occurrences of a String within another String.
      static java.lang.String replaceIgnoreCase​(java.lang.String text, java.lang.String searchString, java.lang.String replacement, int max)
      Case insensitively replaces a String with another String inside a larger String, for the first max values of the search String.
      static java.lang.String replaceOnce​(java.lang.String text, java.lang.String searchString, java.lang.String replacement)
      Replaces a String with another String inside a larger String, once.
      static java.lang.String replaceOnceIgnoreCase​(java.lang.String text, java.lang.String searchString, java.lang.String replacement)
      Case insensitively replaces a String with another String inside a larger String, once.
      static java.lang.String replacePattern​(java.lang.String source, java.lang.String regex, java.lang.String replacement)
      Deprecated.
      Moved to RegExUtils.
      static java.lang.String reverse​(java.lang.String str)
      Reverses a String as per StringBuilder.reverse().
      static java.lang.String reverseDelimited​(java.lang.String str, char separatorChar)
      Reverses a String that is delimited by a specific character.
      static java.lang.String right​(java.lang.String str, int len)
      Gets the rightmost len characters of a String.
      static java.lang.String rightPad​(java.lang.String str, int size)
      Right pad a String with spaces (' ').
      static java.lang.String rightPad​(java.lang.String str, int size, char padChar)
      Right pad a String with a specified character.
      static java.lang.String rightPad​(java.lang.String str, int size, java.lang.String padStr)
      Right pad a String with a specified String.
      static java.lang.String rotate​(java.lang.String str, int shift)
      Rotate (circular shift) a String of shift characters.
      static java.lang.String[] split​(java.lang.String str)
      Splits the provided text into an array, using whitespace as the separator.
      static java.lang.String[] split​(java.lang.String str, char separatorChar)
      Splits the provided text into an array, separator specified.
      static java.lang.String[] split​(java.lang.String str, java.lang.String separatorChars)
      Splits the provided text into an array, separators specified.
      static java.lang.String[] split​(java.lang.String str, java.lang.String separatorChars, int max)
      Splits the provided text into an array with a maximum length, separators specified.
      static java.lang.String[] splitByCharacterType​(java.lang.String str)
      Splits a String by Character type as returned by java.lang.Character.getType(char).
      static java.lang.String[] splitByCharacterTypeCamelCase​(java.lang.String str)
      Splits a String by Character type as returned by java.lang.Character.getType(char).
      static java.lang.String[] splitByWholeSeparator​(java.lang.String str, java.lang.String separator)
      Splits the provided text into an array, separator string specified.
      static java.lang.String[] splitByWholeSeparator​(java.lang.String str, java.lang.String separator, int max)
      Splits the provided text into an array, separator string specified.
      static java.lang.String[] splitByWholeSeparatorPreserveAllTokens​(java.lang.String str, java.lang.String separator)
      Splits the provided text into an array, separator string specified.
      static java.lang.String[] splitByWholeSeparatorPreserveAllTokens​(java.lang.String str, java.lang.String separator, int max)
      Splits the provided text into an array, separator string specified.
      static java.lang.String[] splitPreserveAllTokens​(java.lang.String str)
      Splits the provided text into an array, using whitespace as the separator, preserving all tokens, including empty tokens created by adjacent separators.
      static java.lang.String[] splitPreserveAllTokens​(java.lang.String str, char separatorChar)
      Splits the provided text into an array, separator specified, preserving all tokens, including empty tokens created by adjacent separators.
      static java.lang.String[] splitPreserveAllTokens​(java.lang.String str, java.lang.String separatorChars)
      Splits the provided text into an array, separators specified, preserving all tokens, including empty tokens created by adjacent separators.
      static java.lang.String[] splitPreserveAllTokens​(java.lang.String str, java.lang.String separatorChars, int max)
      Splits the provided text into an array with a maximum length, separators specified, preserving all tokens, including empty tokens created by adjacent separators.
      static boolean startsWith​(java.lang.CharSequence str, java.lang.CharSequence prefix)
      Check if a CharSequence starts with a specified prefix.
      static boolean startsWithAny​(java.lang.CharSequence sequence, java.lang.CharSequence... searchStrings)
      Check if a CharSequence starts with any of the provided case-sensitive prefixes.
      static boolean startsWithIgnoreCase​(java.lang.CharSequence str, java.lang.CharSequence prefix)
      Case insensitive check if a CharSequence starts with a specified prefix.
      static java.lang.String strip​(java.lang.String str)
      Strips whitespace from the start and end of a String.
      static java.lang.String strip​(java.lang.String str, java.lang.String stripChars)
      Strips any of a set of characters from the start and end of a String.
      static java.lang.String stripAccents​(java.lang.String input)
      Removes diacritics (~= accents) from a string.
      static java.lang.String[] stripAll​(java.lang.String... strs)
      Strips whitespace from the start and end of every String in an array.
      static java.lang.String[] stripAll​(java.lang.String[] strs, java.lang.String stripChars)
      Strips any of a set of characters from the start and end of every String in an array.
      static java.lang.String stripEnd​(java.lang.String str, java.lang.String stripChars)
      Strips any of a set of characters from the end of a String.
      static java.lang.String stripStart​(java.lang.String str, java.lang.String stripChars)
      Strips any of a set of characters from the start of a String.
      static java.lang.String stripToEmpty​(java.lang.String str)
      Strips whitespace from the start and end of a String returning an empty String if null input.
      static java.lang.String stripToNull​(java.lang.String str)
      Strips whitespace from the start and end of a String returning null if the String is empty ("") after the strip.
      static java.lang.String substring​(java.lang.String str, int start)
      Gets a substring from the specified String avoiding exceptions.
      static java.lang.String substring​(java.lang.String str, int start, int end)
      Gets a substring from the specified String avoiding exceptions.
      static java.lang.String substringAfter​(java.lang.String str, int separator)
      Gets the substring after the first occurrence of a separator.
      static java.lang.String substringAfter​(java.lang.String str, java.lang.String separator)
      Gets the substring after the first occurrence of a separator.
      static java.lang.String substringAfterLast​(java.lang.String str, int separator)
      Gets the substring after the last occurrence of a separator.
      static java.lang.String substringAfterLast​(java.lang.String str, java.lang.String separator)
      Gets the substring after the last occurrence of a separator.
      static java.lang.String substringBefore​(java.lang.String str, int separator)
      Gets the substring before the first occurrence of a separator.
      static java.lang.String substringBefore​(java.lang.String str, java.lang.String separator)
      Gets the substring before the first occurrence of a separator.
      static java.lang.String substringBeforeLast​(java.lang.String str, java.lang.String separator)
      Gets the substring before the last occurrence of a separator.
      static java.lang.String substringBetween​(java.lang.String str, java.lang.String tag)
      Gets the String that is nested in between two instances of the same String.
      static java.lang.String substringBetween​(java.lang.String str, java.lang.String open, java.lang.String close)
      Gets the String that is nested in between two Strings.
      static java.lang.String[] substringsBetween​(java.lang.String str, java.lang.String open, java.lang.String close)
      Searches a String for substrings delimited by a start and end tag, returning all matching substrings in an array.
      static java.lang.String swapCase​(java.lang.String str)
      Swaps the case of a String changing upper and title case to lower case, and lower case to upper case.
      static int[] toCodePoints​(java.lang.CharSequence cs)
      Converts a CharSequence into an array of code points.
      static java.lang.String toEncodedString​(byte[] bytes, java.nio.charset.Charset charset)
      Converts a byte[] to a String using the specified character encoding.
      static java.lang.String toRootLowerCase​(java.lang.String source)
      Converts the given source String as a lower-case using the Locale.ROOT locale in a null-safe manner.
      static java.lang.String toRootUpperCase​(java.lang.String source)
      Converts the given source String as a upper-case using the Locale.ROOT locale in a null-safe manner.
      static java.lang.String toString​(byte[] bytes, java.lang.String charsetName)
      Deprecated.
      use toEncodedString(byte[], Charset) instead of String constants in your code
      static java.lang.String trim​(java.lang.String str)
      Removes control characters (char <= 32) from both ends of this String, handling null by returning null.
      static java.lang.String trimToEmpty​(java.lang.String str)
      Removes control characters (char <= 32) from both ends of this String returning an empty String ("") if the String is empty ("") after the trim or if it is null.
      static java.lang.String trimToNull​(java.lang.String str)
      Removes control characters (char <= 32) from both ends of this String returning null if the String is empty ("") after the trim or if it is null.
      static java.lang.String truncate​(java.lang.String str, int maxWidth)
      Truncates a String.
      static java.lang.String truncate​(java.lang.String str, int offset, int maxWidth)
      Truncates a String.
      static java.lang.String uncapitalize​(java.lang.String str)
      Uncapitalizes a String, changing the first character to lower case as per Character.toLowerCase(int).
      static java.lang.String unwrap​(java.lang.String str, char wrapChar)
      Unwraps a given string from a character.
      static java.lang.String unwrap​(java.lang.String str, java.lang.String wrapToken)
      Unwraps a given string from anther string.
      static java.lang.String upperCase​(java.lang.String str)
      Converts a String to upper case as per String.toUpperCase().
      static java.lang.String upperCase​(java.lang.String str, java.util.Locale locale)
      Converts a String to upper case as per String.toUpperCase(Locale).
      static java.lang.String valueOf​(char[] value)
      Returns the string representation of the char array or null.
      static java.lang.String wrap​(java.lang.String str, char wrapWith)
      Wraps a string with a char.
      static java.lang.String wrap​(java.lang.String str, java.lang.String wrapWith)
      Wraps a String with another String.
      static java.lang.String wrapIfMissing​(java.lang.String str, char wrapWith)
      Wraps a string with a char if that char is missing from the start or end of the given string.
      static java.lang.String wrapIfMissing​(java.lang.String str, java.lang.String wrapWith)
      Wraps a string with a string if that string is missing from the start or end of the given string.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • StringUtils

        public StringUtils()

        StringUtils instances should NOT be constructed in standard programming. Instead, the class should be used as StringUtils.trim(" foo ");.

        This constructor is public to permit tools that require a JavaBean instance to operate.

    • Method Detail

      • abbreviate

        public static java.lang.String abbreviate​(java.lang.String str,
                                          int maxWidth)

        Abbreviates a String using ellipses. This will turn "Now is the time for all good men" into "Now is the time for..."

        Specifically:

        • If the number of characters in str is less than or equal to maxWidth, return str.
        • Else abbreviate it to (substring(str, 0, max-3) + "...").
        • If maxWidth is less than 4, throw an IllegalArgumentException.
        • In no case will it return a String of length greater than maxWidth.
         StringUtils.abbreviate(null, *)      = null
 StringUtils.abbreviate("", 4)        = ""
 StringUtils.abbreviate("abcdefg", 6) = "abc..."
 StringUtils.abbreviate("abcdefg", 7) = "abcdefg"
 StringUtils.abbreviate("abcdefg", 8) = "abcdefg"
 StringUtils.abbreviate("abcdefg", 4) = "a..."
 StringUtils.abbreviate("abcdefg", 3) = IllegalArgumentException
        Parameters:
        str - the String to check, may be null
        maxWidth - maximum length of result String, must be at least 4
        Returns:
        abbreviated String, null if null String input
        Throws:
        java.lang.IllegalArgumentException - if the width is too small
        Since:
        2.0

      • abbreviate

        public static java.lang.String abbreviate​(java.lang.String str,
                                          int offset,
                                          int maxWidth)

        Abbreviates a String using ellipses. This will turn "Now is the time for all good men" into "...is the time for..."

        Works like abbreviate(String, int), but allows you to specify a "left edge" offset. Note that this left edge is not necessarily going to be the leftmost character in the result, or the first character following the ellipses, but it will appear somewhere in the result.

        In no case will it return a String of length greater than maxWidth. 

         StringUtils.abbreviate(null, *, *)                = null
 StringUtils.abbreviate("", 0, 4)                  = ""
 StringUtils.abbreviate("abcdefghijklmno", -1, 10) = "abcdefg..."
 StringUtils.abbreviate("abcdefghijklmno", 0, 10)  = "abcdefg..."
 StringUtils.abbreviate("abcdefghijklmno", 1, 10)  = "abcdefg..."
 StringUtils.abbreviate("abcdefghijklmno", 4, 10)  = "abcdefg..."
 StringUtils.abbreviate("abcdefghijklmno", 5, 10)  = "...fghi..."
 StringUtils.abbreviate("abcdefghijklmno", 6, 10)  = "...ghij..."
 StringUtils.abbreviate("abcdefghijklmno", 8, 10)  = "...ijklmno"
 StringUtils.abbreviate("abcdefghijklmno", 10, 10) = "...ijklmno"
 StringUtils.abbreviate("abcdefghijklmno", 12, 10) = "...ijklmno"
 StringUtils.abbreviate("abcdefghij", 0, 3)        = IllegalArgumentException
 StringUtils.abbreviate("abcdefghij", 5, 6)        = IllegalArgumentException
        Parameters:
        str - the String to check, may be null
        offset - left edge of source String
        maxWidth - maximum length of result String, must be at least 4
        Returns:
        abbreviated String, null if null String input
        Throws:
        java.lang.IllegalArgumentException - if the width is too small
        Since:
        2.0

      • abbreviate

        public static java.lang.String abbreviate​(java.lang.String str,
                                          java.lang.String abbrevMarker,
                                          int maxWidth)

        Abbreviates a String using another given String as replacement marker. This will turn "Now is the time for all good men" into "Now is the time for..." if "..." was defined as the replacement marker.

        Specifically:

        • If the number of characters in str is less than or equal to maxWidth, return str.
        • Else abbreviate it to (substring(str, 0, max-abbrevMarker.length) + abbrevMarker).
        • If maxWidth is less than abbrevMarker.length + 1, throw an IllegalArgumentException.
        • In no case will it return a String of length greater than maxWidth.
         StringUtils.abbreviate(null, "...", *)      = null
 StringUtils.abbreviate("abcdefg", null, *)  = "abcdefg"
 StringUtils.abbreviate("", "...", 4)        = ""
 StringUtils.abbreviate("abcdefg", ".", 5)   = "abcd."
 StringUtils.abbreviate("abcdefg", ".", 7)   = "abcdefg"
 StringUtils.abbreviate("abcdefg", ".", 8)   = "abcdefg"
 StringUtils.abbreviate("abcdefg", "..", 4)  = "ab.."
 StringUtils.abbreviate("abcdefg", "..", 3)  = "a.."
 StringUtils.abbreviate("abcdefg", "..", 2)  = IllegalArgumentException
 StringUtils.abbreviate("abcdefg", "...", 3) = IllegalArgumentException
        Parameters:
        str - the String to check, may be null
        abbrevMarker - the String used as replacement marker
        maxWidth - maximum length of result String, must be at least abbrevMarker.length + 1
        Returns:
        abbreviated String, null if null String input
        Throws:
        java.lang.IllegalArgumentException - if the width is too small
        Since:
        3.6

      • abbreviate

        public static java.lang.String abbreviate​(java.lang.String str,
                                          java.lang.String abbrevMarker,
                                          int offset,
                                          int maxWidth)

        Abbreviates a String using a given replacement marker. This will turn "Now is the time for all good men" into "...is the time for..." if "..." was defined as the replacement marker.

        Works like abbreviate(String, String, int), but allows you to specify a "left edge" offset. Note that this left edge is not necessarily going to be the leftmost character in the result, or the first character following the replacement marker, but it will appear somewhere in the result.

        In no case will it return a String of length greater than maxWidth. 

         StringUtils.abbreviate(null, null, *, *)                 = null
 StringUtils.abbreviate("abcdefghijklmno", null, *, *)    = "abcdefghijklmno"
 StringUtils.abbreviate("", "...", 0, 4)                  = ""
 StringUtils.abbreviate("abcdefghijklmno", "---", -1, 10) = "abcdefg---"
 StringUtils.abbreviate("abcdefghijklmno", ",", 0, 10)    = "abcdefghi,"
 StringUtils.abbreviate("abcdefghijklmno", ",", 1, 10)    = "abcdefghi,"
 StringUtils.abbreviate("abcdefghijklmno", ",", 2, 10)    = "abcdefghi,"
 StringUtils.abbreviate("abcdefghijklmno", "::", 4, 10)   = "::efghij::"
 StringUtils.abbreviate("abcdefghijklmno", "...", 6, 10)  = "...ghij..."
 StringUtils.abbreviate("abcdefghijklmno", "*", 9, 10)    = "*ghijklmno"
 StringUtils.abbreviate("abcdefghijklmno", "'", 10, 10)   = "'ghijklmno"
 StringUtils.abbreviate("abcdefghijklmno", "!", 12, 10)   = "!ghijklmno"
 StringUtils.abbreviate("abcdefghij", "abra", 0, 4)       = IllegalArgumentException
 StringUtils.abbreviate("abcdefghij", "...", 5, 6)        = IllegalArgumentException
        Parameters:
        str - the String to check, may be null
        abbrevMarker - the String used as replacement marker
        offset - left edge of source String
        maxWidth - maximum length of result String, must be at least 4
        Returns:
        abbreviated String, null if null String input
        Throws:
        java.lang.IllegalArgumentException - if the width is too small
        Since:
        3.6

      • abbreviateMiddle

        public static java.lang.String abbreviateMiddle​(java.lang.String str,
                                                java.lang.String middle,
                                                int length)

        Abbreviates a String to the length passed, replacing the middle characters with the supplied replacement String.

        This abbreviation only occurs if the following criteria is met:

        • Neither the String for abbreviation nor the replacement String are null or empty
        • The length to truncate to is less than the length of the supplied String
        • The length to truncate to is greater than 0
        • The abbreviated String will have enough room for the length supplied replacement String and the first and last characters of the supplied String for abbreviation

        Otherwise, the returned String will be the same as the supplied String for abbreviation. 

         StringUtils.abbreviateMiddle(null, null, 0)      = null
 StringUtils.abbreviateMiddle("abc", null, 0)      = "abc"
 StringUtils.abbreviateMiddle("abc", ".", 0)      = "abc"
 StringUtils.abbreviateMiddle("abc", ".", 3)      = "abc"
 StringUtils.abbreviateMiddle("abcdef", ".", 4)     = "ab.f"
        Parameters:
        str - the String to abbreviate, may be null
        middle - the String to replace the middle characters with, may be null
        length - the length to abbreviate str to.
        Returns:
        the abbreviated String if the above criteria is met, or the original String supplied for abbreviation.
        Since:
        2.5

      • capitalize

        public static java.lang.String capitalize​(java.lang.String str)

        Capitalizes a String changing the first character to title case as per Character.toTitleCase(int). No other characters are changed.

        For a word based algorithm, see WordUtils.capitalize(String). A null input String returns null. 

         StringUtils.capitalize(null)  = null
 StringUtils.capitalize("")    = ""
 StringUtils.capitalize("cat") = "Cat"
 StringUtils.capitalize("cAt") = "CAt"
 StringUtils.capitalize("'cat'") = "'cat'"
        Parameters:
        str - the String to capitalize, may be null
        Returns:
        the capitalized String, null if null String input
        Since:
        2.0
        See Also:
        WordUtils.capitalize(String), uncapitalize(String)

      • center

        public static java.lang.String center​(java.lang.String str,
                                      int size)

        Centers a String in a larger String of size size using the space character (' ').

        If the size is less than the String length, the original String is returned. A null String returns null. A negative size is treated as zero.

        Equivalent to center(str, size, " "). 

         StringUtils.center(null, *)   = null
 StringUtils.center("", 4)     = "    "
 StringUtils.center("ab", -1)  = "ab"
 StringUtils.center("ab", 4)   = " ab "
 StringUtils.center("abcd", 2) = "abcd"
 StringUtils.center("a", 4)    = " a  "
        Parameters:
        str - the String to center, may be null
        size - the int size of new String, negative treated as zero
        Returns:
        centered String, null if null String input

      • center

        public static java.lang.String center​(java.lang.String str,
                                      int size,
                                      char padChar)

        Centers a String in a larger String of size size. Uses a supplied character as the value to pad the String with.

        If the size is less than the String length, the String is returned. A null String returns null. A negative size is treated as zero. 

         StringUtils.center(null, *, *)     = null
 StringUtils.center("", 4, ' ')     = "    "
 StringUtils.center("ab", -1, ' ')  = "ab"
 StringUtils.center("ab", 4, ' ')   = " ab "
 StringUtils.center("abcd", 2, ' ') = "abcd"
 StringUtils.center("a", 4, ' ')    = " a  "
 StringUtils.center("a", 4, 'y')    = "yayy"
        Parameters:
        str - the String to center, may be null
        size - the int size of new String, negative treated as zero
        padChar - the character to pad the new String with
        Returns:
        centered String, null if null String input
        Since:
        2.0

      • center

        public static java.lang.String center​(java.lang.String str,
                                      int size,
                                      java.lang.String padStr)

        Centers a String in a larger String of size size. Uses a supplied String as the value to pad the String with.

        If the size is less than the String length, the String is returned. A null String returns null. A negative size is treated as zero. 

         StringUtils.center(null, *, *)     = null
 StringUtils.center("", 4, " ")     = "    "
 StringUtils.center("ab", -1, " ")  = "ab"
 StringUtils.center("ab", 4, " ")   = " ab "
 StringUtils.center("abcd", 2, " ") = "abcd"
 StringUtils.center("a", 4, " ")    = " a  "
 StringUtils.center("a", 4, "yz")   = "yayz"
 StringUtils.center("abc", 7, null) = "  abc  "
 StringUtils.center("abc", 7, "")   = "  abc  "
        Parameters:
        str - the String to center, may be null
        size - the int size of new String, negative treated as zero
        padStr - the String to pad the new String with, must not be null or empty
        Returns:
        centered String, null if null String input
        Throws:
        java.lang.IllegalArgumentException - if padStr is null or empty

      • chomp

        public static java.lang.String chomp​(java.lang.String str)

        Removes one newline from end of a String if it's there, otherwise leave it alone. A newline is "\n", "\r", or "\r\n".

        NOTE: This method changed in 2.0. It now more closely matches Perl chomp. 

         StringUtils.chomp(null)          = null
 StringUtils.chomp("")            = ""
 StringUtils.chomp("abc \r")      = "abc "
 StringUtils.chomp("abc\n")       = "abc"
 StringUtils.chomp("abc\r\n")     = "abc"
 StringUtils.chomp("abc\r\n\r\n") = "abc\r\n"
 StringUtils.chomp("abc\n\r")     = "abc\n"
 StringUtils.chomp("abc\n\rabc")  = "abc\n\rabc"
 StringUtils.chomp("\r")          = ""
 StringUtils.chomp("\n")          = ""
 StringUtils.chomp("\r\n")        = ""
        Parameters:
        str - the String to chomp a newline from, may be null
        Returns:
        String without newline, null if null String input

      • chomp

        @Deprecated
public static java.lang.String chomp​(java.lang.String str,
                                     java.lang.String separator)
        Deprecated.
        This feature will be removed in Lang 4.0, use removeEnd(String, String) instead

        Removes separator from the end of str if it's there, otherwise leave it alone.

        NOTE: This method changed in version 2.0. It now more closely matches Perl chomp. For the previous behavior, use substringBeforeLast(String, String). This method uses String.endsWith(String). 

         StringUtils.chomp(null, *)         = null
 StringUtils.chomp("", *)           = ""
 StringUtils.chomp("foobar", "bar") = "foo"
 StringUtils.chomp("foobar", "baz") = "foobar"
 StringUtils.chomp("foo", "foo")    = ""
 StringUtils.chomp("foo ", "foo")   = "foo "
 StringUtils.chomp(" foo", "foo")   = " "
 StringUtils.chomp("foo", "foooo")  = "foo"
 StringUtils.chomp("foo", "")       = "foo"
 StringUtils.chomp("foo", null)     = "foo"
        Parameters:
        str - the String to chomp from, may be null
        separator - separator String, may be null
        Returns:
        String without trailing separator, null if null String input

      • chop

        public static java.lang.String chop​(java.lang.String str)

        Remove the last character from a String.

        If the String ends in \r\n, then remove both of them. 

         StringUtils.chop(null)          = null
 StringUtils.chop("")            = ""
 StringUtils.chop("abc \r")      = "abc "
 StringUtils.chop("abc\n")       = "abc"
 StringUtils.chop("abc\r\n")     = "abc"
 StringUtils.chop("abc")         = "ab"
 StringUtils.chop("abc\nabc")    = "abc\nab"
 StringUtils.chop("a")           = ""
 StringUtils.chop("\r")          = ""
 StringUtils.chop("\n")          = ""
 StringUtils.chop("\r\n")        = ""
        Parameters:
        str - the String to chop last character from, may be null
        Returns:
        String without last character, null if null String input

      • compare

        public static int compare​(java.lang.String str1,
                          java.lang.String str2)

        Compare two Strings lexicographically, as per String.compareTo(String), returning :

        • int = 0, if str1 is equal to str2 (or both null)
        • int < 0, if str1 is less than str2
        • int > 0, if str1 is greater than str2

        This is a null safe version of : 

         str1.compareTo(str2)

        null value is considered less than non-null value. Two null references are considered equal. 

         StringUtils.compare(null, null)   = 0
 StringUtils.compare(null , "a")   < 0
 StringUtils.compare("a", null)    > 0
 StringUtils.compare("abc", "abc") = 0
 StringUtils.compare("a", "b")     < 0
 StringUtils.compare("b", "a")     > 0
 StringUtils.compare("a", "B")     > 0
 StringUtils.compare("ab", "abc")  < 0
        Parameters:
        str1 - the String to compare from
        str2 - the String to compare to
        Returns:
        < 0, 0, > 0, if str1 is respectively less, equal or greater than str2
        Since:
        3.5
        See Also:
        compare(String, String, boolean), String.compareTo(String)

      • compare

        public static int compare​(java.lang.String str1,
                          java.lang.String str2,
                          boolean nullIsLess)

        Compare two Strings lexicographically, as per String.compareTo(String), returning :

        • int = 0, if str1 is equal to str2 (or both null)
        • int < 0, if str1 is less than str2
        • int > 0, if str1 is greater than str2

        This is a null safe version of : 

         str1.compareTo(str2)

        null inputs are handled according to the nullIsLess parameter. Two null references are considered equal. 

         StringUtils.compare(null, null, *)     = 0
 StringUtils.compare(null , "a", true)  < 0
 StringUtils.compare(null , "a", false) > 0
 StringUtils.compare("a", null, true)   > 0
 StringUtils.compare("a", null, false)  < 0
 StringUtils.compare("abc", "abc", *)   = 0
 StringUtils.compare("a", "b", *)       < 0
 StringUtils.compare("b", "a", *)       > 0
 StringUtils.compare("a", "B", *)       > 0
 StringUtils.compare("ab", "abc", *)    < 0
        Parameters:
        str1 - the String to compare from
        str2 - the String to compare to
        nullIsLess - whether consider null value less than non-null value
        Returns:
        < 0, 0, > 0, if str1 is respectively less, equal ou greater than str2
        Since:
        3.5
        See Also:
        String.compareTo(String)

      • compareIgnoreCase

        public static int compareIgnoreCase​(java.lang.String str1,
                                    java.lang.String str2)

        Compare two Strings lexicographically, ignoring case differences, as per String.compareToIgnoreCase(String), returning :

        • int = 0, if str1 is equal to str2 (or both null)
        • int < 0, if str1 is less than str2
        • int > 0, if str1 is greater than str2

        This is a null safe version of : 

         str1.compareToIgnoreCase(str2)

        null value is considered less than non-null value. Two null references are considered equal. Comparison is case insensitive. 

         StringUtils.compareIgnoreCase(null, null)   = 0
 StringUtils.compareIgnoreCase(null , "a")   < 0
 StringUtils.compareIgnoreCase("a", null)    > 0
 StringUtils.compareIgnoreCase("abc", "abc") = 0
 StringUtils.compareIgnoreCase("abc", "ABC") = 0
 StringUtils.compareIgnoreCase("a", "b")     < 0
 StringUtils.compareIgnoreCase("b", "a")     > 0
 StringUtils.compareIgnoreCase("a", "B")     < 0
 StringUtils.compareIgnoreCase("A", "b")     < 0
 StringUtils.compareIgnoreCase("ab", "ABC")  < 0
        Parameters:
        str1 - the String to compare from
        str2 - the String to compare to
        Returns:
        < 0, 0, > 0, if str1 is respectively less, equal ou greater than str2, ignoring case differences.
        Since:
        3.5
        See Also:
        compareIgnoreCase(String, String, boolean), String.compareToIgnoreCase(String)

      • compareIgnoreCase

        public static int compareIgnoreCase​(java.lang.String str1,
                                    java.lang.String str2,
                                    boolean nullIsLess)

        Compare two Strings lexicographically, ignoring case differences, as per String.compareToIgnoreCase(String), returning :

        • int = 0, if str1 is equal to str2 (or both null)
        • int < 0, if str1 is less than str2
        • int > 0, if str1 is greater than str2

        This is a null safe version of : 

         str1.compareToIgnoreCase(str2)

        null inputs are handled according to the nullIsLess parameter. Two null references are considered equal. Comparison is case insensitive. 

         StringUtils.compareIgnoreCase(null, null, *)     = 0
 StringUtils.compareIgnoreCase(null , "a", true)  < 0
 StringUtils.compareIgnoreCase(null , "a", false) > 0
 StringUtils.compareIgnoreCase("a", null, true)   > 0
 StringUtils.compareIgnoreCase("a", null, false)  < 0
 StringUtils.compareIgnoreCase("abc", "abc", *)   = 0
 StringUtils.compareIgnoreCase("abc", "ABC", *)   = 0
 StringUtils.compareIgnoreCase("a", "b", *)       < 0
 StringUtils.compareIgnoreCase("b", "a", *)       > 0
 StringUtils.compareIgnoreCase("a", "B", *)       < 0
 StringUtils.compareIgnoreCase("A", "b", *)       < 0
 StringUtils.compareIgnoreCase("ab", "abc", *)    < 0
        Parameters:
        str1 - the String to compare from
        str2 - the String to compare to
        nullIsLess - whether consider null value less than non-null value
        Returns:
        < 0, 0, > 0, if str1 is respectively less, equal ou greater than str2, ignoring case differences.
        Since:
        3.5
        See Also:
        String.compareToIgnoreCase(String)

      • contains

        public static boolean contains​(java.lang.CharSequence seq,
                               java.lang.CharSequence searchSeq)

        Checks if CharSequence contains a search CharSequence, handling null. This method uses String.indexOf(String) if possible.

        A null CharSequence will return false. 

         StringUtils.contains(null, *)     = false
 StringUtils.contains(*, null)     = false
 StringUtils.contains("", "")      = true
 StringUtils.contains("abc", "")   = true
 StringUtils.contains("abc", "a")  = true
 StringUtils.contains("abc", "z")  = false
        Parameters:
        seq - the CharSequence to check, may be null
        searchSeq - the CharSequence to find, may be null
        Returns:
        true if the CharSequence contains the search CharSequence, false if not or null string input
        Since:
        2.0, 3.0 Changed signature from contains(String, String) to contains(CharSequence, CharSequence)

      • contains

        public static boolean contains​(java.lang.CharSequence seq,
                               int searchChar)

        Checks if CharSequence contains a search character, handling null. This method uses String.indexOf(int) if possible.

        A null or empty ("") CharSequence will return false. 

         StringUtils.contains(null, *)    = false
 StringUtils.contains("", *)      = false
 StringUtils.contains("abc", 'a') = true
 StringUtils.contains("abc", 'z') = false
        Parameters:
        seq - the CharSequence to check, may be null
        searchChar - the character to find
        Returns:
        true if the CharSequence contains the search character, false if not or null string input
        Since:
        2.0, 3.0 Changed signature from contains(String, int) to contains(CharSequence, int)

      • containsAny

        public static boolean containsAny​(java.lang.CharSequence cs,
                                  char... searchChars)

        Checks if the CharSequence contains any character in the given set of characters.

        A null CharSequence will return false. A null or zero length search array will return false. 

         StringUtils.containsAny(null, *)                  = false
 StringUtils.containsAny("", *)                    = false
 StringUtils.containsAny(*, null)                  = false
 StringUtils.containsAny(*, [])                    = false
 StringUtils.containsAny("zzabyycdxx", ['z', 'a']) = true
 StringUtils.containsAny("zzabyycdxx", ['b', 'y']) = true
 StringUtils.containsAny("zzabyycdxx", ['z', 'y']) = true
 StringUtils.containsAny("aba", ['z'])             = false
        Parameters:
        cs - the CharSequence to check, may be null
        searchChars - the chars to search for, may be null
        Returns:
        the true if any of the chars are found, false if no match or null input
        Since:
        2.4, 3.0 Changed signature from containsAny(String, char[]) to containsAny(CharSequence, char...)

      • containsAny

        public static boolean containsAny​(java.lang.CharSequence cs,
                                  java.lang.CharSequence searchChars)

        Checks if the CharSequence contains any character in the given set of characters.

        A null CharSequence will return false. A null search CharSequence will return false. 

         StringUtils.containsAny(null, *)               = false
 StringUtils.containsAny("", *)                 = false
 StringUtils.containsAny(*, null)               = false
 StringUtils.containsAny(*, "")                 = false
 StringUtils.containsAny("zzabyycdxx", "za")    = true
 StringUtils.containsAny("zzabyycdxx", "by")    = true
 StringUtils.containsAny("zzabyycdxx", "zy")    = true
 StringUtils.containsAny("zzabyycdxx", "\tx")   = true
 StringUtils.containsAny("zzabyycdxx", "$.#yF") = true
 StringUtils.containsAny("aba", "z")            = false
        Parameters:
        cs - the CharSequence to check, may be null
        searchChars - the chars to search for, may be null
        Returns:
        the true if any of the chars are found, false if no match or null input
        Since:
        2.4, 3.0 Changed signature from containsAny(String, String) to containsAny(CharSequence, CharSequence)

      • containsAny

        public static boolean containsAny​(java.lang.CharSequence cs,
                                  java.lang.CharSequence... searchCharSequences)

        Checks if the CharSequence contains any of the CharSequences in the given array.

        A null cs CharSequence will return false. A null or zero length search array will return false. 

         StringUtils.containsAny(null, *)            = false
 StringUtils.containsAny("", *)              = false
 StringUtils.containsAny(*, null)            = false
 StringUtils.containsAny(*, [])              = false
 StringUtils.containsAny("abcd", "ab", null) = true
 StringUtils.containsAny("abcd", "ab", "cd") = true
 StringUtils.containsAny("abc", "d", "abc")  = true
        Parameters:
        cs - The CharSequence to check, may be null
        searchCharSequences - The array of CharSequences to search for, may be null. Individual CharSequences may be null as well.
        Returns:
        true if any of the search CharSequences are found, false otherwise
        Since:
        3.4

      • containsAnyIgnoreCase

        public static boolean containsAnyIgnoreCase​(java.lang.CharSequence cs,
                                            java.lang.CharSequence... searchCharSequences)

        Checks if the CharSequence contains any of the CharSequences in the given array, ignoring case.

        A null cs CharSequence will return false. A null or zero length search array will return false. 

         StringUtils.containsAny(null, *)            = false
 StringUtils.containsAny("", *)              = false
 StringUtils.containsAny(*, null)            = false
 StringUtils.containsAny(*, [])              = false
 StringUtils.containsAny("abcd", "ab", null) = true
 StringUtils.containsAny("abcd", "ab", "cd") = true
 StringUtils.containsAny("abc", "d", "abc")  = true
 StringUtils.containsAny("abc", "D", "ABC")  = true
 StringUtils.containsAny("ABC", "d", "abc")  = true
        Parameters:
        cs - The CharSequence to check, may be null
        searchCharSequences - The array of CharSequences to search for, may be null. Individual CharSequences may be null as well.
        Returns:
        true if any of the search CharSequences are found, false otherwise
        Since:
        3.12.0

      • containsIgnoreCase

        public static boolean containsIgnoreCase​(java.lang.CharSequence str,
                                         java.lang.CharSequence searchStr)

        Checks if CharSequence contains a search CharSequence irrespective of case, handling null. Case-insensitivity is defined as by String.equalsIgnoreCase(String).

        A null CharSequence will return false. 

         StringUtils.containsIgnoreCase(null, *) = false
 StringUtils.containsIgnoreCase(*, null) = false
 StringUtils.containsIgnoreCase("", "") = true
 StringUtils.containsIgnoreCase("abc", "") = true
 StringUtils.containsIgnoreCase("abc", "a") = true
 StringUtils.containsIgnoreCase("abc", "z") = false
 StringUtils.containsIgnoreCase("abc", "A") = true
 StringUtils.containsIgnoreCase("abc", "Z") = false
        Parameters:
        str - the CharSequence to check, may be null
        searchStr - the CharSequence to find, may be null
        Returns:
        true if the CharSequence contains the search CharSequence irrespective of case or false if not or null string input
        Since:
        3.0 Changed signature from containsIgnoreCase(String, String) to containsIgnoreCase(CharSequence, CharSequence)

      • containsNone

        public static boolean containsNone​(java.lang.CharSequence cs,
                                   char... searchChars)

        Checks that the CharSequence does not contain certain characters.

        A null CharSequence will return true. A null invalid character array will return true. An empty CharSequence (length()=0) always returns true. 

         StringUtils.containsNone(null, *)       = true
 StringUtils.containsNone(*, null)       = true
 StringUtils.containsNone("", *)         = true
 StringUtils.containsNone("ab", '')      = true
 StringUtils.containsNone("abab", 'xyz') = true
 StringUtils.containsNone("ab1", 'xyz')  = true
 StringUtils.containsNone("abz", 'xyz')  = false
        Parameters:
        cs - the CharSequence to check, may be null
        searchChars - an array of invalid chars, may be null
        Returns:
        true if it contains none of the invalid chars, or is null
        Since:
        2.0, 3.0 Changed signature from containsNone(String, char[]) to containsNone(CharSequence, char...)

      • containsNone

        public static boolean containsNone​(java.lang.CharSequence cs,
                                   java.lang.String invalidChars)

        Checks that the CharSequence does not contain certain characters.

        A null CharSequence will return true. A null invalid character array will return true. An empty String ("") always returns true. 

         StringUtils.containsNone(null, *)       = true
 StringUtils.containsNone(*, null)       = true
 StringUtils.containsNone("", *)         = true
 StringUtils.containsNone("ab", "")      = true
 StringUtils.containsNone("abab", "xyz") = true
 StringUtils.containsNone("ab1", "xyz")  = true
 StringUtils.containsNone("abz", "xyz")  = false
        Parameters:
        cs - the CharSequence to check, may be null
        invalidChars - a String of invalid chars, may be null
        Returns:
        true if it contains none of the invalid chars, or is null
        Since:
        2.0, 3.0 Changed signature from containsNone(String, String) to containsNone(CharSequence, String)

      • containsOnly

        public static boolean containsOnly​(java.lang.CharSequence cs,
                                   char... valid)

        Checks if the CharSequence contains only certain characters.

        A null CharSequence will return false. A null valid character array will return false. An empty CharSequence (length()=0) always returns true. 

         StringUtils.containsOnly(null, *)       = false
 StringUtils.containsOnly(*, null)       = false
 StringUtils.containsOnly("", *)         = true
 StringUtils.containsOnly("ab", '')      = false
 StringUtils.containsOnly("abab", 'abc') = true
 StringUtils.containsOnly("ab1", 'abc')  = false
 StringUtils.containsOnly("abz", 'abc')  = false
        Parameters:
        cs - the String to check, may be null
        valid - an array of valid chars, may be null
        Returns:
        true if it only contains valid chars and is non-null
        Since:
        3.0 Changed signature from containsOnly(String, char[]) to containsOnly(CharSequence, char...)

      • containsOnly

        public static boolean containsOnly​(java.lang.CharSequence cs,
                                   java.lang.String validChars)

        Checks if the CharSequence contains only certain characters.

        A null CharSequence will return false. A null valid character String will return false. An empty String (length()=0) always returns true. 

         StringUtils.containsOnly(null, *)       = false
 StringUtils.containsOnly(*, null)       = false
 StringUtils.containsOnly("", *)         = true
 StringUtils.containsOnly("ab", "")      = false
 StringUtils.containsOnly("abab", "abc") = true
 StringUtils.containsOnly("ab1", "abc")  = false
 StringUtils.containsOnly("abz", "abc")  = false
        Parameters:
        cs - the CharSequence to check, may be null
        validChars - a String of valid chars, may be null
        Returns:
        true if it only contains valid chars and is non-null
        Since:
        2.0, 3.0 Changed signature from containsOnly(String, String) to containsOnly(CharSequence, String)

      • containsWhitespace

        public static boolean containsWhitespace​(java.lang.CharSequence seq)

        Check whether the given CharSequence contains any whitespace characters.

        Whitespace is defined by Character.isWhitespace(char).

        Parameters:
        seq - the CharSequence to check (may be null)
        Returns:
        true if the CharSequence is not empty and contains at least 1 (breaking) whitespace character
        Since:
        3.0

      • countMatches

        public static int countMatches​(java.lang.CharSequence str,
                               char ch)

        Counts how many times the char appears in the given string.

        A null or empty ("") String input returns 0. 

         StringUtils.countMatches(null, *)       = 0
 StringUtils.countMatches("", *)         = 0
 StringUtils.countMatches("abba", 0)  = 0
 StringUtils.countMatches("abba", 'a')   = 2
 StringUtils.countMatches("abba", 'b')  = 2
 StringUtils.countMatches("abba", 'x') = 0
        Parameters:
        str - the CharSequence to check, may be null
        ch - the char to count
        Returns:
        the number of occurrences, 0 if the CharSequence is null
        Since:
        3.4

      • countMatches

        public static int countMatches​(java.lang.CharSequence str,
                               java.lang.CharSequence sub)

        Counts how many times the substring appears in the larger string. Note that the code only counts non-overlapping matches.

        A null or empty ("") String input returns 0. 

         StringUtils.countMatches(null, *)       = 0
 StringUtils.countMatches("", *)         = 0
 StringUtils.countMatches("abba", null)  = 0
 StringUtils.countMatches("abba", "")    = 0
 StringUtils.countMatches("abba", "a")   = 2
 StringUtils.countMatches("abba", "ab")  = 1
 StringUtils.countMatches("abba", "xxx") = 0
 StringUtils.countMatches("ababa", "aba") = 1
        Parameters:
        str - the CharSequence to check, may be null
        sub - the substring to count, may be null
        Returns:
        the number of occurrences, 0 if either CharSequence is null
        Since:
        3.0 Changed signature from countMatches(String, String) to countMatches(CharSequence, CharSequence)

      • defaultIfBlank

        public static <T extends java.lang.CharSequence> T defaultIfBlank​(T str,
                                                                  T defaultStr)

        Returns either the passed in CharSequence, or if the CharSequence is whitespace, empty ("") or null, the value of defaultStr.

        Whitespace is defined by Character.isWhitespace(char). 

         StringUtils.defaultIfBlank(null, "NULL")  = "NULL"
 StringUtils.defaultIfBlank("", "NULL")    = "NULL"
 StringUtils.defaultIfBlank(" ", "NULL")   = "NULL"
 StringUtils.defaultIfBlank("bat", "NULL") = "bat"
 StringUtils.defaultIfBlank("", null)      = null
        Type Parameters:
        T - the specific kind of CharSequence
        Parameters:
        str - the CharSequence to check, may be null
        defaultStr - the default CharSequence to return if the input is whitespace, empty ("") or null, may be null
        Returns:
        the passed in CharSequence, or the default
        See Also:
        defaultString(String, String)

      • defaultIfEmpty

        public static <T extends java.lang.CharSequence> T defaultIfEmpty​(T str,
                                                                  T defaultStr)

        Returns either the passed in CharSequence, or if the CharSequence is empty or null, the value of defaultStr. 

         StringUtils.defaultIfEmpty(null, "NULL")  = "NULL"
 StringUtils.defaultIfEmpty("", "NULL")    = "NULL"
 StringUtils.defaultIfEmpty(" ", "NULL")   = " "
 StringUtils.defaultIfEmpty("bat", "NULL") = "bat"
 StringUtils.defaultIfEmpty("", null)      = null
        Type Parameters:
        T - the specific kind of CharSequence
        Parameters:
        str - the CharSequence to check, may be null
        defaultStr - the default CharSequence to return if the input is empty ("") or null, may be null
        Returns:
        the passed in CharSequence, or the default
        See Also:
        defaultString(String, String)

      • defaultString

        public static java.lang.String defaultString​(java.lang.String str)

        Returns either the passed in String, or if the String is null, an empty String (""). 

         StringUtils.defaultString(null)  = ""
 StringUtils.defaultString("")    = ""
 StringUtils.defaultString("bat") = "bat"
        Parameters:
        str - the String to check, may be null
        Returns:
        the passed in String, or the empty String if it was null
        See Also:
        ObjectUtils.toString(Object), String.valueOf(Object)

      • defaultString

        public static java.lang.String defaultString​(java.lang.String str,
                                             java.lang.String defaultStr)

        Returns either the passed in String, or if the String is null, the value of defaultStr. 

         StringUtils.defaultString(null, "NULL")  = "NULL"
 StringUtils.defaultString("", "NULL")    = ""
 StringUtils.defaultString("bat", "NULL") = "bat"
        Parameters:
        str - the String to check, may be null
        defaultStr - the default String to return if the input is null, may be null
        Returns:
        the passed in String, or the default if it was null
        See Also:
        ObjectUtils.toString(Object,String), String.valueOf(Object)

      • deleteWhitespace

        public static java.lang.String deleteWhitespace​(java.lang.String str)

        Deletes all whitespaces from a String as defined by Character.isWhitespace(char). 

         StringUtils.deleteWhitespace(null)         = null
 StringUtils.deleteWhitespace("")           = ""
 StringUtils.deleteWhitespace("abc")        = "abc"
 StringUtils.deleteWhitespace("   ab  c  ") = "abc"
        Parameters:
        str - the String to delete whitespace from, may be null
        Returns:
        the String without whitespaces, null if null String input

      • difference

        public static java.lang.String difference​(java.lang.String str1,
                                          java.lang.String str2)

        Compares two Strings, and returns the portion where they differ. More precisely, return the remainder of the second String, starting from where it's different from the first. This means that the difference between "abc" and "ab" is the empty String and not "c".

        For example, difference("i am a machine", "i am a robot") -> "robot". 

         StringUtils.difference(null, null) = null
 StringUtils.difference("", "") = ""
 StringUtils.difference("", "abc") = "abc"
 StringUtils.difference("abc", "") = ""
 StringUtils.difference("abc", "abc") = ""
 StringUtils.difference("abc", "ab") = ""
 StringUtils.difference("ab", "abxyz") = "xyz"
 StringUtils.difference("abcde", "abxyz") = "xyz"
 StringUtils.difference("abcde", "xyz") = "xyz"
        Parameters:
        str1 - the first String, may be null
        str2 - the second String, may be null
        Returns:
        the portion of str2 where it differs from str1; returns the empty String if they are equal
        Since:
        2.0
        See Also:
        indexOfDifference(CharSequence,CharSequence)

      • endsWith

        public static boolean endsWith​(java.lang.CharSequence str,
                               java.lang.CharSequence suffix)

        Check if a CharSequence ends with a specified suffix.

        nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case sensitive. 

         StringUtils.endsWith(null, null)      = true
 StringUtils.endsWith(null, "def")     = false
 StringUtils.endsWith("abcdef", null)  = false
 StringUtils.endsWith("abcdef", "def") = true
 StringUtils.endsWith("ABCDEF", "def") = false
 StringUtils.endsWith("ABCDEF", "cde") = false
 StringUtils.endsWith("ABCDEF", "")    = true
        Parameters:
        str - the CharSequence to check, may be null
        suffix - the suffix to find, may be null
        Returns:
        true if the CharSequence ends with the suffix, case sensitive, or both null
        Since:
        2.4, 3.0 Changed signature from endsWith(String, String) to endsWith(CharSequence, CharSequence)
        See Also:
        String.endsWith(String)

      • endsWithAny

        public static boolean endsWithAny​(java.lang.CharSequence sequence,
                                  java.lang.CharSequence... searchStrings)

        Check if a CharSequence ends with any of the provided case-sensitive suffixes. 

         StringUtils.endsWithAny(null, null)      = false
 StringUtils.endsWithAny(null, new String[] {"abc"})  = false
 StringUtils.endsWithAny("abcxyz", null)     = false
 StringUtils.endsWithAny("abcxyz", new String[] {""}) = true
 StringUtils.endsWithAny("abcxyz", new String[] {"xyz"}) = true
 StringUtils.endsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
 StringUtils.endsWithAny("abcXYZ", "def", "XYZ") = true
 StringUtils.endsWithAny("abcXYZ", "def", "xyz") = false
        Parameters:
        sequence - the CharSequence to check, may be null
        searchStrings - the case-sensitive CharSequences to find, may be empty or contain null
        Returns:
        true if the input sequence is null AND no searchStrings are provided, or the input sequence ends in any of the provided case-sensitive searchStrings.
        Since:
        3.0
        See Also:
        endsWith(CharSequence, CharSequence)

      • endsWithIgnoreCase

        public static boolean endsWithIgnoreCase​(java.lang.CharSequence str,
                                         java.lang.CharSequence suffix)

        Case insensitive check if a CharSequence ends with a specified suffix.

        nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case insensitive. 

         StringUtils.endsWithIgnoreCase(null, null)      = true
 StringUtils.endsWithIgnoreCase(null, "def")     = false
 StringUtils.endsWithIgnoreCase("abcdef", null)  = false
 StringUtils.endsWithIgnoreCase("abcdef", "def") = true
 StringUtils.endsWithIgnoreCase("ABCDEF", "def") = true
 StringUtils.endsWithIgnoreCase("ABCDEF", "cde") = false
        Parameters:
        str - the CharSequence to check, may be null
        suffix - the suffix to find, may be null
        Returns:
        true if the CharSequence ends with the suffix, case insensitive, or both null
        Since:
        2.4, 3.0 Changed signature from endsWithIgnoreCase(String, String) to endsWithIgnoreCase(CharSequence, CharSequence)
        See Also:
        String.endsWith(String)

      • equals

        public static boolean equals​(java.lang.CharSequence cs1,
                             java.lang.CharSequence cs2)

        Compares two CharSequences, returning true if they represent equal sequences of characters.

        nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case sensitive. 

         StringUtils.equals(null, null)   = true
 StringUtils.equals(null, "abc")  = false
 StringUtils.equals("abc", null)  = false
 StringUtils.equals("abc", "abc") = true
 StringUtils.equals("abc", "ABC") = false
        Parameters:
        cs1 - the first CharSequence, may be null
        cs2 - the second CharSequence, may be null
        Returns:
        true if the CharSequences are equal (case-sensitive), or both null
        Since:
        3.0 Changed signature from equals(String, String) to equals(CharSequence, CharSequence)
        See Also:
        Object.equals(Object), equalsIgnoreCase(CharSequence, CharSequence)

      • equalsAny

        public static boolean equalsAny​(java.lang.CharSequence string,
                                java.lang.CharSequence... searchStrings)

        Compares given string to a CharSequences vararg of searchStrings, returning true if the string is equal to any of the searchStrings. 

         StringUtils.equalsAny(null, (CharSequence[]) null) = false
 StringUtils.equalsAny(null, null, null)    = true
 StringUtils.equalsAny(null, "abc", "def")  = false
 StringUtils.equalsAny("abc", null, "def")  = false
 StringUtils.equalsAny("abc", "abc", "def") = true
 StringUtils.equalsAny("abc", "ABC", "DEF") = false
        Parameters:
        string - to compare, may be null.
        searchStrings - a vararg of strings, may be null.
        Returns:
        true if the string is equal (case-sensitive) to any other element of searchStrings; false if searchStrings is null or contains no matches.
        Since:
        3.5

      • equalsAnyIgnoreCase

        public static boolean equalsAnyIgnoreCase​(java.lang.CharSequence string,
                                          java.lang.CharSequence... searchStrings)

        Compares given string to a CharSequences vararg of searchStrings, returning true if the string is equal to any of the searchStrings, ignoring case. 

         StringUtils.equalsAnyIgnoreCase(null, (CharSequence[]) null) = false
 StringUtils.equalsAnyIgnoreCase(null, null, null)    = true
 StringUtils.equalsAnyIgnoreCase(null, "abc", "def")  = false
 StringUtils.equalsAnyIgnoreCase("abc", null, "def")  = false
 StringUtils.equalsAnyIgnoreCase("abc", "abc", "def") = true
 StringUtils.equalsAnyIgnoreCase("abc", "ABC", "DEF") = true
        Parameters:
        string - to compare, may be null.
        searchStrings - a vararg of strings, may be null.
        Returns:
        true if the string is equal (case-insensitive) to any other element of searchStrings; false if searchStrings is null or contains no matches.
        Since:
        3.5

      • equalsIgnoreCase

        public static boolean equalsIgnoreCase​(java.lang.CharSequence cs1,
                                       java.lang.CharSequence cs2)

        Compares two CharSequences, returning true if they represent equal sequences of characters, ignoring case.

        nulls are handled without exceptions. Two null references are considered equal. The comparison is case insensitive. 

         StringUtils.equalsIgnoreCase(null, null)   = true
 StringUtils.equalsIgnoreCase(null, "abc")  = false
 StringUtils.equalsIgnoreCase("abc", null)  = false
 StringUtils.equalsIgnoreCase("abc", "abc") = true
 StringUtils.equalsIgnoreCase("abc", "ABC") = true
        Parameters:
        cs1 - the first CharSequence, may be null
        cs2 - the second CharSequence, may be null
        Returns:
        true if the CharSequences are equal (case-insensitive), or both null
        Since:
        3.0 Changed signature from equalsIgnoreCase(String, String) to equalsIgnoreCase(CharSequence, CharSequence)
        See Also:
        equals(CharSequence, CharSequence)

      • firstNonBlank

        @SafeVarargs
public static <T extends java.lang.CharSequence> T firstNonBlank​(T... values)

        Returns the first value in the array which is not empty (""), null or whitespace only.

        Whitespace is defined by Character.isWhitespace(char).

        If all values are blank or the array is null or empty then null is returned. 

         StringUtils.firstNonBlank(null, null, null)     = null
 StringUtils.firstNonBlank(null, "", " ")        = null
 StringUtils.firstNonBlank("abc")                = "abc"
 StringUtils.firstNonBlank(null, "xyz")          = "xyz"
 StringUtils.firstNonBlank(null, "", " ", "xyz") = "xyz"
 StringUtils.firstNonBlank(null, "xyz", "abc")   = "xyz"
 StringUtils.firstNonBlank()                     = null
        Type Parameters:
        T - the specific kind of CharSequence
        Parameters:
        values - the values to test, may be null or empty
        Returns:
        the first value from values which is not blank, or null if there are no non-blank values
        Since:
        3.8

      • firstNonEmpty

        @SafeVarargs
public static <T extends java.lang.CharSequence> T firstNonEmpty​(T... values)

        Returns the first value in the array which is not empty.

        If all values are empty or the array is null or empty then null is returned. 

         StringUtils.firstNonEmpty(null, null, null)   = null
 StringUtils.firstNonEmpty(null, null, "")     = null
 StringUtils.firstNonEmpty(null, "", " ")      = " "
 StringUtils.firstNonEmpty("abc")              = "abc"
 StringUtils.firstNonEmpty(null, "xyz")        = "xyz"
 StringUtils.firstNonEmpty("", "xyz")          = "xyz"
 StringUtils.firstNonEmpty(null, "xyz", "abc") = "xyz"
 StringUtils.firstNonEmpty()                   = null
        Type Parameters:
        T - the specific kind of CharSequence
        Parameters:
        values - the values to test, may be null or empty
        Returns:
        the first value from values which is not empty, or null if there are no non-empty values
        Since:
        3.8

      • getBytes

        public static byte[] getBytes​(java.lang.String string,
                              java.nio.charset.Charset charset)
        Calls String.getBytes(Charset) in a null-safe manner.
        Parameters:
        string - input string
        charset - The Charset to encode the String. If null, then use the default Charset.
        Returns:
        The empty byte[] if string is null, the result of String.getBytes(Charset) otherwise.
        Since:
        3.10
        See Also:
        String.getBytes(Charset)

      • getBytes

        public static byte[] getBytes​(java.lang.String string,
                              java.lang.String charset)
                       throws java.io.UnsupportedEncodingException
        Calls String.getBytes(String) in a null-safe manner.
        Parameters:
        string - input string
        charset - The Charset name to encode the String. If null, then use the default Charset.
        Returns:
        The empty byte[] if string is null, the result of String.getBytes(String) otherwise.
        Throws:
        java.io.UnsupportedEncodingException - Thrown when the named charset is not supported.
        Since:
        3.10
        See Also:
        String.getBytes(String)

      • getCommonPrefix

        public static java.lang.String getCommonPrefix​(java.lang.String... strs)

        Compares all Strings in an array and returns the initial sequence of characters that is common to all of them.

        For example, getCommonPrefix(new String[] {"i am a machine", "i am a robot"}) -&gt; "i am a " 

         StringUtils.getCommonPrefix(null) = ""
 StringUtils.getCommonPrefix(new String[] {}) = ""
 StringUtils.getCommonPrefix(new String[] {"abc"}) = "abc"
 StringUtils.getCommonPrefix(new String[] {null, null}) = ""
 StringUtils.getCommonPrefix(new String[] {"", ""}) = ""
 StringUtils.getCommonPrefix(new String[] {"", null}) = ""
 StringUtils.getCommonPrefix(new String[] {"abc", null, null}) = ""
 StringUtils.getCommonPrefix(new String[] {null, null, "abc"}) = ""
 StringUtils.getCommonPrefix(new String[] {"", "abc"}) = ""
 StringUtils.getCommonPrefix(new String[] {"abc", ""}) = ""
 StringUtils.getCommonPrefix(new String[] {"abc", "abc"}) = "abc"
 StringUtils.getCommonPrefix(new String[] {"abc", "a"}) = "a"
 StringUtils.getCommonPrefix(new String[] {"ab", "abxyz"}) = "ab"
 StringUtils.getCommonPrefix(new String[] {"abcde", "abxyz"}) = "ab"
 StringUtils.getCommonPrefix(new String[] {"abcde", "xyz"}) = ""
 StringUtils.getCommonPrefix(new String[] {"xyz", "abcde"}) = ""
 StringUtils.getCommonPrefix(new String[] {"i am a machine", "i am a robot"}) = "i am a "
        Parameters:
        strs - array of String objects, entries may be null
        Returns:
        the initial sequence of characters that are common to all Strings in the array; empty String if the array is null, the elements are all null or if there is no common prefix.
        Since:
        2.4

      • getDigits

        public static java.lang.String getDigits​(java.lang.String str)

        Checks if a String str contains Unicode digits, if yes then concatenate all the digits in str and return it as a String.

        An empty ("") String will be returned if no digits found in str. 

         StringUtils.getDigits(null)  = null
 StringUtils.getDigits("")    = ""
 StringUtils.getDigits("abc") = ""
 StringUtils.getDigits("1000$") = "1000"
 StringUtils.getDigits("1123~45") = "112345"
 StringUtils.getDigits("(541) 754-3010") = "5417543010"
 StringUtils.getDigits("१२३") = "१२३"
        Parameters:
        str - the String to extract digits from, may be null
        Returns:
        String with only digits, or an empty ("") String if no digits found, or null String if str is null
        Since:
        3.6

      • getFuzzyDistance

        @Deprecated
public static int getFuzzyDistance​(java.lang.CharSequence term,
                                   java.lang.CharSequence query,
                                   java.util.Locale locale)
        Deprecated.
        as of 3.6, use commons-text FuzzyScore instead

        Find the Fuzzy Distance which indicates the similarity score between two Strings.

        This string matching algorithm is similar to the algorithms of editors such as Sublime Text, TextMate, Atom and others. One point is given for every matched character. Subsequent matches yield two bonus points. A higher score indicates a higher similarity. 

         StringUtils.getFuzzyDistance(null, null, null)                                    = IllegalArgumentException
 StringUtils.getFuzzyDistance("", "", Locale.ENGLISH)                              = 0
 StringUtils.getFuzzyDistance("Workshop", "b", Locale.ENGLISH)                     = 0
 StringUtils.getFuzzyDistance("Room", "o", Locale.ENGLISH)                         = 1
 StringUtils.getFuzzyDistance("Workshop", "w", Locale.ENGLISH)                     = 1
 StringUtils.getFuzzyDistance("Workshop", "ws", Locale.ENGLISH)                    = 2
 StringUtils.getFuzzyDistance("Workshop", "wo", Locale.ENGLISH)                    = 4
 StringUtils.getFuzzyDistance("Apache Software Foundation", "asf", Locale.ENGLISH) = 3
        Parameters:
        term - a full term that should be matched against, must not be null
        query - the query that will be matched against a term, must not be null
        locale - This string matching logic is case insensitive. A locale is necessary to normalize both Strings to lower case.
        Returns:
        result score
        Throws:
        java.lang.IllegalArgumentException - if either String input null or Locale input null
        Since:
        3.4

      • getIfBlank

        public static <T extends java.lang.CharSequence> T getIfBlank​(T str,
                                                              java.util.function.Supplier<T> defaultSupplier)

        Returns either the passed in CharSequence, or if the CharSequence is whitespace, empty ("") or null, the value supplied by defaultStrSupplier.

        Whitespace is defined by Character.isWhitespace(char).

        Caller responsible for thread-safety and exception handling of default value supplier 

         
 StringUtils.getIfBlank(null, () -> "NULL")   = "NULL"
 StringUtils.getIfBlank("", () -> "NULL")     = "NULL"
 StringUtils.getIfBlank(" ", () -> "NULL")    = "NULL"
 StringUtils.getIfBlank("bat", () -> "NULL")  = "bat"
 StringUtils.getIfBlank("", () -> null)       = null
 StringUtils.getIfBlank("", null)             = null
        Type Parameters:
        T - the specific kind of CharSequence
        Parameters:
        str - the CharSequence to check, may be null
        defaultSupplier - the supplier of default CharSequence to return if the input is whitespace, empty ("") or null, may be null
        Returns:
        the passed in CharSequence, or the default
        Since:
        3.10
        See Also:
        defaultString(String, String)

      • getIfEmpty

        public static <T extends java.lang.CharSequence> T getIfEmpty​(T str,
                                                              java.util.function.Supplier<T> defaultSupplier)

        Returns either the passed in CharSequence, or if the CharSequence is empty or null, the value supplied by defaultStrSupplier.

        Caller responsible for thread-safety and exception handling of default value supplier 

         
 StringUtils.getIfEmpty(null, () -> "NULL")    = "NULL"
 StringUtils.getIfEmpty("", () -> "NULL")      = "NULL"
 StringUtils.getIfEmpty(" ", () -> "NULL")     = " "
 StringUtils.getIfEmpty("bat", () -> "NULL")   = "bat"
 StringUtils.getIfEmpty("", () -> null)        = null
 StringUtils.getIfEmpty("", null)              = null
        Type Parameters:
        T - the specific kind of CharSequence
        Parameters:
        str - the CharSequence to check, may be null
        defaultSupplier - the supplier of default CharSequence to return if the input is empty ("") or null, may be null
        Returns:
        the passed in CharSequence, or the default
        Since:
        3.10
        See Also:
        defaultString(String, String)

      • getJaroWinklerDistance

        @Deprecated
public static double getJaroWinklerDistance​(java.lang.CharSequence first,
                                            java.lang.CharSequence second)
        Deprecated.
        as of 3.6, use commons-text JaroWinklerDistance instead

        Find the Jaro Winkler Distance which indicates the similarity score between two Strings.

        The Jaro measure is the weighted sum of percentage of matched characters from each file and transposed characters. Winkler increased this measure for matching initial characters.

        This implementation is based on the Jaro Winkler similarity algorithm from http://en.wikipedia.org/wiki/Jaro%E2%80%93Winkler_distance. 

         StringUtils.getJaroWinklerDistance(null, null)          = IllegalArgumentException
 StringUtils.getJaroWinklerDistance("", "")              = 0.0
 StringUtils.getJaroWinklerDistance("", "a")             = 0.0
 StringUtils.getJaroWinklerDistance("aaapppp", "")       = 0.0
 StringUtils.getJaroWinklerDistance("frog", "fog")       = 0.93
 StringUtils.getJaroWinklerDistance("fly", "ant")        = 0.0
 StringUtils.getJaroWinklerDistance("elephant", "hippo") = 0.44
 StringUtils.getJaroWinklerDistance("hippo", "elephant") = 0.44
 StringUtils.getJaroWinklerDistance("hippo", "zzzzzzzz") = 0.0
 StringUtils.getJaroWinklerDistance("hello", "hallo")    = 0.88
 StringUtils.getJaroWinklerDistance("ABC Corporation", "ABC Corp") = 0.93
 StringUtils.getJaroWinklerDistance("D N H Enterprises Inc", "D & H Enterprises, Inc.") = 0.95
 StringUtils.getJaroWinklerDistance("My Gym Children's Fitness Center", "My Gym. Childrens Fitness") = 0.92
 StringUtils.getJaroWinklerDistance("PENNSYLVANIA", "PENNCISYLVNIA") = 0.88
        Parameters:
        first - the first String, must not be null
        second - the second String, must not be null
        Returns:
        result distance
        Throws:
        java.lang.IllegalArgumentException - if either String input null
        Since:
        3.3

      • getLevenshteinDistance

        @Deprecated
public static int getLevenshteinDistance​(java.lang.CharSequence s,
                                         java.lang.CharSequence t)
        Deprecated.
        as of 3.6, use commons-text LevenshteinDistance instead

        Find the Levenshtein distance between two Strings.

        This is the number of changes needed to change one String into another, where each change is a single character modification (deletion, insertion or substitution).

        The implementation uses a single-dimensional array of length s.length() + 1. See http://blog.softwx.net/2014/12/optimizing-levenshtein-algorithm-in-c.html for details. 

         StringUtils.getLevenshteinDistance(null, *)             = IllegalArgumentException
 StringUtils.getLevenshteinDistance(*, null)             = IllegalArgumentException
 StringUtils.getLevenshteinDistance("", "")              = 0
 StringUtils.getLevenshteinDistance("", "a")             = 1
 StringUtils.getLevenshteinDistance("aaapppp", "")       = 7
 StringUtils.getLevenshteinDistance("frog", "fog")       = 1
 StringUtils.getLevenshteinDistance("fly", "ant")        = 3
 StringUtils.getLevenshteinDistance("elephant", "hippo") = 7
 StringUtils.getLevenshteinDistance("hippo", "elephant") = 7
 StringUtils.getLevenshteinDistance("hippo", "zzzzzzzz") = 8
 StringUtils.getLevenshteinDistance("hello", "hallo")    = 1
        Parameters:
        s - the first String, must not be null
        t - the second String, must not be null
        Returns:
        result distance
        Throws:
        java.lang.IllegalArgumentException - if either String input null
        Since:
        3.0 Changed signature from getLevenshteinDistance(String, String) to getLevenshteinDistance(CharSequence, CharSequence)

      • getLevenshteinDistance

        @Deprecated
public static int getLevenshteinDistance​(java.lang.CharSequence s,
                                         java.lang.CharSequence t,
                                         int threshold)
        Deprecated.
        as of 3.6, use commons-text LevenshteinDistance instead

        Find the Levenshtein distance between two Strings if it's less than or equal to a given threshold.

        This is the number of changes needed to change one String into another, where each change is a single character modification (deletion, insertion or substitution).

        This implementation follows from Algorithms on Strings, Trees and Sequences by Dan Gusfield and Chas Emerick's implementation of the Levenshtein distance algorithm from http://www.merriampark.com/ld.htm 

         StringUtils.getLevenshteinDistance(null, *, *)             = IllegalArgumentException
 StringUtils.getLevenshteinDistance(*, null, *)             = IllegalArgumentException
 StringUtils.getLevenshteinDistance(*, *, -1)               = IllegalArgumentException
 StringUtils.getLevenshteinDistance("", "", 0)              = 0
 StringUtils.getLevenshteinDistance("aaapppp", "", 8)       = 7
 StringUtils.getLevenshteinDistance("aaapppp", "", 7)       = 7
 StringUtils.getLevenshteinDistance("aaapppp", "", 6))      = -1
 StringUtils.getLevenshteinDistance("elephant", "hippo", 7) = 7
 StringUtils.getLevenshteinDistance("elephant", "hippo", 6) = -1
 StringUtils.getLevenshteinDistance("hippo", "elephant", 7) = 7
 StringUtils.getLevenshteinDistance("hippo", "elephant", 6) = -1
        Parameters:
        s - the first String, must not be null
        t - the second String, must not be null
        threshold - the target threshold, must not be negative
        Returns:
        result distance, or -1 if the distance would be greater than the threshold
        Throws:
        java.lang.IllegalArgumentException - if either String input null or negative threshold

      • indexOf

        public static int indexOf​(java.lang.CharSequence seq,
                          java.lang.CharSequence searchSeq)

        Finds the first index within a CharSequence, handling null. This method uses String.indexOf(String, int) if possible.

        A null CharSequence will return -1. 

         StringUtils.indexOf(null, *)          = -1
 StringUtils.indexOf(*, null)          = -1
 StringUtils.indexOf("", "")           = 0
 StringUtils.indexOf("", *)            = -1 (except when * = "")
 StringUtils.indexOf("aabaabaa", "a")  = 0
 StringUtils.indexOf("aabaabaa", "b")  = 2
 StringUtils.indexOf("aabaabaa", "ab") = 1
 StringUtils.indexOf("aabaabaa", "")   = 0
        Parameters:
        seq - the CharSequence to check, may be null
        searchSeq - the CharSequence to find, may be null
        Returns:
        the first index of the search CharSequence, -1 if no match or null string input
        Since:
        2.0, 3.0 Changed signature from indexOf(String, String) to indexOf(CharSequence, CharSequence)

      • indexOf

        public static int indexOf​(java.lang.CharSequence seq,
                          java.lang.CharSequence searchSeq,
                          int startPos)

        Finds the first index within a CharSequence, handling null. This method uses String.indexOf(String, int) if possible.

        A null CharSequence will return -1. A negative start position is treated as zero. An empty ("") search CharSequence always matches. A start position greater than the string length only matches an empty search CharSequence. 

         StringUtils.indexOf(null, *, *)          = -1
 StringUtils.indexOf(*, null, *)          = -1
 StringUtils.indexOf("", "", 0)           = 0
 StringUtils.indexOf("", *, 0)            = -1 (except when * = "")
 StringUtils.indexOf("aabaabaa", "a", 0)  = 0
 StringUtils.indexOf("aabaabaa", "b", 0)  = 2
 StringUtils.indexOf("aabaabaa", "ab", 0) = 1
 StringUtils.indexOf("aabaabaa", "b", 3)  = 5
 StringUtils.indexOf("aabaabaa", "b", 9)  = -1
 StringUtils.indexOf("aabaabaa", "b", -1) = 2
 StringUtils.indexOf("aabaabaa", "", 2)   = 2
 StringUtils.indexOf("abc", "", 9)        = 3
        Parameters:
        seq - the CharSequence to check, may be null
        searchSeq - the CharSequence to find, may be null
        startPos - the start position, negative treated as zero
        Returns:
        the first index of the search CharSequence (always ≥ startPos), -1 if no match or null string input
        Since:
        2.0, 3.0 Changed signature from indexOf(String, String, int) to indexOf(CharSequence, CharSequence, int)

      • indexOf

        public static int indexOf​(java.lang.CharSequence seq,
                          int searchChar)
        Returns the index within seq of the first occurrence of the specified character. If a character with value searchChar occurs in the character sequence represented by seq CharSequence object, then the index (in Unicode code units) of the first such occurrence is returned. For values of searchChar in the range from 0 to 0xFFFF (inclusive), this is the smallest value k such that: 
         this.charAt(k) == searchChar
        is true. For other values of searchChar, it is the smallest value k such that: 
         this.codePointAt(k) == searchChar
        is true. In either case, if no such character occurs in seq, then INDEX_NOT_FOUND (-1) is returned.

        Furthermore, a null or empty ("") CharSequence will return INDEX_NOT_FOUND (-1). 

         StringUtils.indexOf(null, *)         = -1
 StringUtils.indexOf("", *)           = -1
 StringUtils.indexOf("aabaabaa", 'a') = 0
 StringUtils.indexOf("aabaabaa", 'b') = 2
        Parameters:
        seq - the CharSequence to check, may be null
        searchChar - the character to find
        Returns:
        the first index of the search character, -1 if no match or null string input
        Since:
        2.0, 3.0 Changed signature from indexOf(String, int) to indexOf(CharSequence, int), 3.6 Updated CharSequenceUtils call to behave more like String

      • indexOf

        public static int indexOf​(java.lang.CharSequence seq,
                          int searchChar,
                          int startPos)
        Returns the index within seq of the first occurrence of the specified character, starting the search at the specified index.

        If a character with value searchChar occurs in the character sequence represented by the seq CharSequence object at an index no smaller than startPos, then the index of the first such occurrence is returned. For values of searchChar in the range from 0 to 0xFFFF (inclusive), this is the smallest value k such that: 

         (this.charAt(k) == searchChar) && (k >= startPos)
        is true. For other values of searchChar, it is the smallest value k such that: 
         (this.codePointAt(k) == searchChar) && (k >= startPos)
        is true. In either case, if no such character occurs in seq at or after position startPos, then -1 is returned.

        There is no restriction on the value of startPos. If it is negative, it has the same effect as if it were zero: this entire string may be searched. If it is greater than the length of this string, it has the same effect as if it were equal to the length of this string: (INDEX_NOT_FOUND) -1 is returned. Furthermore, a null or empty ("") CharSequence will return (INDEX_NOT_FOUND) -1.

        All indices are specified in char values (Unicode code units). 

         StringUtils.indexOf(null, *, *)          = -1
 StringUtils.indexOf("", *, *)            = -1
 StringUtils.indexOf("aabaabaa", 'b', 0)  = 2
 StringUtils.indexOf("aabaabaa", 'b', 3)  = 5
 StringUtils.indexOf("aabaabaa", 'b', 9)  = -1
 StringUtils.indexOf("aabaabaa", 'b', -1) = 2
        Parameters:
        seq - the CharSequence to check, may be null
        searchChar - the character to find
        startPos - the start position, negative treated as zero
        Returns:
        the first index of the search character (always ≥ startPos), -1 if no match or null string input
        Since:
        2.0, 3.0 Changed signature from indexOf(String, int, int) to indexOf(CharSequence, int, int), 3.6 Updated CharSequenceUtils call to behave more like String

      • indexOfAny

        public static int indexOfAny​(java.lang.CharSequence cs,
                             char... searchChars)

        Search a CharSequence to find the first index of any character in the given set of characters.

        A null String will return -1. A null or zero length search array will return -1. 

         StringUtils.indexOfAny(null, *)                  = -1
 StringUtils.indexOfAny("", *)                    = -1
 StringUtils.indexOfAny(*, null)                  = -1
 StringUtils.indexOfAny(*, [])                    = -1
 StringUtils.indexOfAny("zzabyycdxx", ['z', 'a']) = 0
 StringUtils.indexOfAny("zzabyycdxx", ['b', 'y']) = 3
 StringUtils.indexOfAny("aba", ['z'])             = -1
        Parameters:
        cs - the CharSequence to check, may be null
        searchChars - the chars to search for, may be null
        Returns:
        the index of any of the chars, -1 if no match or null input
        Since:
        2.0, 3.0 Changed signature from indexOfAny(String, char[]) to indexOfAny(CharSequence, char...)

      • indexOfAny

        public static int indexOfAny​(java.lang.CharSequence str,
                             java.lang.CharSequence... searchStrs)

        Find the first index of any of a set of potential substrings.

        A null CharSequence will return -1. A null or zero length search array will return -1. A null search array entry will be ignored, but a search array containing "" will return 0 if str is not null. This method uses String.indexOf(String) if possible. 

         StringUtils.indexOfAny(null, *)                      = -1
 StringUtils.indexOfAny(*, null)                      = -1
 StringUtils.indexOfAny(*, [])                        = -1
 StringUtils.indexOfAny("zzabyycdxx", ["ab", "cd"])   = 2
 StringUtils.indexOfAny("zzabyycdxx", ["cd", "ab"])   = 2
 StringUtils.indexOfAny("zzabyycdxx", ["mn", "op"])   = -1
 StringUtils.indexOfAny("zzabyycdxx", ["zab", "aby"]) = 1
 StringUtils.indexOfAny("zzabyycdxx", [""])           = 0
 StringUtils.indexOfAny("", [""])                     = 0
 StringUtils.indexOfAny("", ["a"])                    = -1
        Parameters:
        str - the CharSequence to check, may be null
        searchStrs - the CharSequences to search for, may be null
        Returns:
        the first index of any of the searchStrs in str, -1 if no match
        Since:
        3.0 Changed signature from indexOfAny(String, String[]) to indexOfAny(CharSequence, CharSequence...)

      • indexOfAny

        public static int indexOfAny​(java.lang.CharSequence cs,
                             java.lang.String searchChars)

        Search a CharSequence to find the first index of any character in the given set of characters.

        A null String will return -1. A null search string will return -1. 

         StringUtils.indexOfAny(null, *)            = -1
 StringUtils.indexOfAny("", *)              = -1
 StringUtils.indexOfAny(*, null)            = -1
 StringUtils.indexOfAny(*, "")              = -1
 StringUtils.indexOfAny("zzabyycdxx", "za") = 0
 StringUtils.indexOfAny("zzabyycdxx", "by") = 3
 StringUtils.indexOfAny("aba", "z")         = -1
        Parameters:
        cs - the CharSequence to check, may be null
        searchChars - the chars to search for, may be null
        Returns:
        the index of any of the chars, -1 if no match or null input
        Since:
        2.0, 3.0 Changed signature from indexOfAny(String, String) to indexOfAny(CharSequence, String)

      • indexOfAnyBut

        public static int indexOfAnyBut​(java.lang.CharSequence cs,
                                char... searchChars)

        Searches a CharSequence to find the first index of any character not in the given set of characters.

        A null CharSequence will return -1. A null or zero length search array will return -1. 

         StringUtils.indexOfAnyBut(null, *)                              = -1
 StringUtils.indexOfAnyBut("", *)                                = -1
 StringUtils.indexOfAnyBut(*, null)                              = -1
 StringUtils.indexOfAnyBut(*, [])                                = -1
 StringUtils.indexOfAnyBut("zzabyycdxx", new char[] {'z', 'a'} ) = 3
 StringUtils.indexOfAnyBut("aba", new char[] {'z'} )             = 0
 StringUtils.indexOfAnyBut("aba", new char[] {'a', 'b'} )        = -1
        Parameters:
        cs - the CharSequence to check, may be null
        searchChars - the chars to search for, may be null
        Returns:
        the index of any of the chars, -1 if no match or null input
        Since:
        2.0, 3.0 Changed signature from indexOfAnyBut(String, char[]) to indexOfAnyBut(CharSequence, char...)

      • indexOfAnyBut

        public static int indexOfAnyBut​(java.lang.CharSequence seq,
                                java.lang.CharSequence searchChars)

        Search a CharSequence to find the first index of any character not in the given set of characters.

        A null CharSequence will return -1. A null or empty search string will return -1. 

         StringUtils.indexOfAnyBut(null, *)            = -1
 StringUtils.indexOfAnyBut("", *)              = -1
 StringUtils.indexOfAnyBut(*, null)            = -1
 StringUtils.indexOfAnyBut(*, "")              = -1
 StringUtils.indexOfAnyBut("zzabyycdxx", "za") = 3
 StringUtils.indexOfAnyBut("zzabyycdxx", "")   = -1
 StringUtils.indexOfAnyBut("aba", "ab")        = -1
        Parameters:
        seq - the CharSequence to check, may be null
        searchChars - the chars to search for, may be null
        Returns:
        the index of any of the chars, -1 if no match or null input
        Since:
        2.0, 3.0 Changed signature from indexOfAnyBut(String, String) to indexOfAnyBut(CharSequence, CharSequence)

      • indexOfDifference

        public static int indexOfDifference​(java.lang.CharSequence... css)

        Compares all CharSequences in an array and returns the index at which the CharSequences begin to differ.

        For example, indexOfDifference(new String[] {"i am a machine", "i am a robot"}) -> 7 

         StringUtils.indexOfDifference(null) = -1
 StringUtils.indexOfDifference(new String[] {}) = -1
 StringUtils.indexOfDifference(new String[] {"abc"}) = -1
 StringUtils.indexOfDifference(new String[] {null, null}) = -1
 StringUtils.indexOfDifference(new String[] {"", ""}) = -1
 StringUtils.indexOfDifference(new String[] {"", null}) = 0
 StringUtils.indexOfDifference(new String[] {"abc", null, null}) = 0
 StringUtils.indexOfDifference(new String[] {null, null, "abc"}) = 0
 StringUtils.indexOfDifference(new String[] {"", "abc"}) = 0
 StringUtils.indexOfDifference(new String[] {"abc", ""}) = 0
 StringUtils.indexOfDifference(new String[] {"abc", "abc"}) = -1
 StringUtils.indexOfDifference(new String[] {"abc", "a"}) = 1
 StringUtils.indexOfDifference(new String[] {"ab", "abxyz"}) = 2
 StringUtils.indexOfDifference(new String[] {"abcde", "abxyz"}) = 2
 StringUtils.indexOfDifference(new String[] {"abcde", "xyz"}) = 0
 StringUtils.indexOfDifference(new String[] {"xyz", "abcde"}) = 0
 StringUtils.indexOfDifference(new String[] {"i am a machine", "i am a robot"}) = 7
        Parameters:
        css - array of CharSequences, entries may be null
        Returns:
        the index where the strings begin to differ; -1 if they are all equal
        Since:
        2.4, 3.0 Changed signature from indexOfDifference(String...) to indexOfDifference(CharSequence...)

      • indexOfDifference

        public static int indexOfDifference​(java.lang.CharSequence cs1,
                                    java.lang.CharSequence cs2)

        Compares two CharSequences, and returns the index at which the CharSequences begin to differ.

        For example, indexOfDifference("i am a machine", "i am a robot") -> 7 

         StringUtils.indexOfDifference(null, null) = -1
 StringUtils.indexOfDifference("", "") = -1
 StringUtils.indexOfDifference("", "abc") = 0
 StringUtils.indexOfDifference("abc", "") = 0
 StringUtils.indexOfDifference("abc", "abc") = -1
 StringUtils.indexOfDifference("ab", "abxyz") = 2
 StringUtils.indexOfDifference("abcde", "abxyz") = 2
 StringUtils.indexOfDifference("abcde", "xyz") = 0
        Parameters:
        cs1 - the first CharSequence, may be null
        cs2 - the second CharSequence, may be null
        Returns:
        the index where cs1 and cs2 begin to differ; -1 if they are equal
        Since:
        2.0, 3.0 Changed signature from indexOfDifference(String, String) to indexOfDifference(CharSequence, CharSequence)

      • indexOfIgnoreCase

        public static int indexOfIgnoreCase​(java.lang.CharSequence str,
                                    java.lang.CharSequence searchStr)

        Case in-sensitive find of the first index within a CharSequence.

        A null CharSequence will return -1. A negative start position is treated as zero. An empty ("") search CharSequence always matches. A start position greater than the string length only matches an empty search CharSequence. 

         StringUtils.indexOfIgnoreCase(null, *)          = -1
 StringUtils.indexOfIgnoreCase(*, null)          = -1
 StringUtils.indexOfIgnoreCase("", "")           = 0
 StringUtils.indexOfIgnoreCase("aabaabaa", "a")  = 0
 StringUtils.indexOfIgnoreCase("aabaabaa", "b")  = 2
 StringUtils.indexOfIgnoreCase("aabaabaa", "ab") = 1
        Parameters:
        str - the CharSequence to check, may be null
        searchStr - the CharSequence to find, may be null
        Returns:
        the first index of the search CharSequence, -1 if no match or null string input
        Since:
        2.5, 3.0 Changed signature from indexOfIgnoreCase(String, String) to indexOfIgnoreCase(CharSequence, CharSequence)

      • indexOfIgnoreCase

        public static int indexOfIgnoreCase​(java.lang.CharSequence str,
                                    java.lang.CharSequence searchStr,
                                    int startPos)

        Case in-sensitive find of the first index within a CharSequence from the specified position.

        A null CharSequence will return -1. A negative start position is treated as zero. An empty ("") search CharSequence always matches. A start position greater than the string length only matches an empty search CharSequence. 

         StringUtils.indexOfIgnoreCase(null, *, *)          = -1
 StringUtils.indexOfIgnoreCase(*, null, *)          = -1
 StringUtils.indexOfIgnoreCase("", "", 0)           = 0
 StringUtils.indexOfIgnoreCase("aabaabaa", "A", 0)  = 0
 StringUtils.indexOfIgnoreCase("aabaabaa", "B", 0)  = 2
 StringUtils.indexOfIgnoreCase("aabaabaa", "AB", 0) = 1
 StringUtils.indexOfIgnoreCase("aabaabaa", "B", 3)  = 5
 StringUtils.indexOfIgnoreCase("aabaabaa", "B", 9)  = -1
 StringUtils.indexOfIgnoreCase("aabaabaa", "B", -1) = 2
 StringUtils.indexOfIgnoreCase("aabaabaa", "", 2)   = 2
 StringUtils.indexOfIgnoreCase("abc", "", 9)        = -1
        Parameters:
        str - the CharSequence to check, may be null
        searchStr - the CharSequence to find, may be null
        startPos - the start position, negative treated as zero
        Returns:
        the first index of the search CharSequence (always ≥ startPos), -1 if no match or null string input
        Since:
        2.5, 3.0 Changed signature from indexOfIgnoreCase(String, String, int) to indexOfIgnoreCase(CharSequence, CharSequence, int)

      • isAllBlank

        public static boolean isAllBlank​(java.lang.CharSequence... css)

        Checks if all of the CharSequences are empty (""), null or whitespace only.

        Whitespace is defined by Character.isWhitespace(char). 

         StringUtils.isAllBlank(null)             = true
 StringUtils.isAllBlank(null, "foo")      = false
 StringUtils.isAllBlank(null, null)       = true
 StringUtils.isAllBlank("", "bar")        = false
 StringUtils.isAllBlank("bob", "")        = false
 StringUtils.isAllBlank("  bob  ", null)  = false
 StringUtils.isAllBlank(" ", "bar")       = false
 StringUtils.isAllBlank("foo", "bar")     = false
 StringUtils.isAllBlank(new String[] {})  = true
        Parameters:
        css - the CharSequences to check, may be null or empty
        Returns:
        true if all of the CharSequences are empty or null or whitespace only
        Since:
        3.6

      • isAllEmpty

        public static boolean isAllEmpty​(java.lang.CharSequence... css)

        Checks if all of the CharSequences are empty ("") or null. 

         StringUtils.isAllEmpty(null)             = true
 StringUtils.isAllEmpty(null, "")         = true
 StringUtils.isAllEmpty(new String[] {})  = true
 StringUtils.isAllEmpty(null, "foo")      = false
 StringUtils.isAllEmpty("", "bar")        = false
 StringUtils.isAllEmpty("bob", "")        = false
 StringUtils.isAllEmpty("  bob  ", null)  = false
 StringUtils.isAllEmpty(" ", "bar")       = false
 StringUtils.isAllEmpty("foo", "bar")     = false
        Parameters:
        css - the CharSequences to check, may be null or empty
        Returns:
        true if all of the CharSequences are empty or null
        Since:
        3.6

      • isAllLowerCase

        public static boolean isAllLowerCase​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only lowercase characters.

        null will return false. An empty CharSequence (length()=0) will return false. 

         StringUtils.isAllLowerCase(null)   = false
 StringUtils.isAllLowerCase("")     = false
 StringUtils.isAllLowerCase("  ")   = false
 StringUtils.isAllLowerCase("abc")  = true
 StringUtils.isAllLowerCase("abC")  = false
 StringUtils.isAllLowerCase("ab c") = false
 StringUtils.isAllLowerCase("ab1c") = false
 StringUtils.isAllLowerCase("ab/c") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if only contains lowercase characters, and is non-null
        Since:
        2.5, 3.0 Changed signature from isAllLowerCase(String) to isAllLowerCase(CharSequence)

      • isAllUpperCase

        public static boolean isAllUpperCase​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only uppercase characters.

        null will return false. An empty String (length()=0) will return false. 

         StringUtils.isAllUpperCase(null)   = false
 StringUtils.isAllUpperCase("")     = false
 StringUtils.isAllUpperCase("  ")   = false
 StringUtils.isAllUpperCase("ABC")  = true
 StringUtils.isAllUpperCase("aBC")  = false
 StringUtils.isAllUpperCase("A C")  = false
 StringUtils.isAllUpperCase("A1C")  = false
 StringUtils.isAllUpperCase("A/C")  = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if only contains uppercase characters, and is non-null
        Since:
        2.5, 3.0 Changed signature from isAllUpperCase(String) to isAllUpperCase(CharSequence)

      • isAlpha

        public static boolean isAlpha​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only Unicode letters.

        null will return false. An empty CharSequence (length()=0) will return false. 

         StringUtils.isAlpha(null)   = false
 StringUtils.isAlpha("")     = false
 StringUtils.isAlpha("  ")   = false
 StringUtils.isAlpha("abc")  = true
 StringUtils.isAlpha("ab2c") = false
 StringUtils.isAlpha("ab-c") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if only contains letters, and is non-null
        Since:
        3.0 Changed signature from isAlpha(String) to isAlpha(CharSequence), 3.0 Changed "" to return false and not true

      • isAlphanumeric

        public static boolean isAlphanumeric​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only Unicode letters or digits.

        null will return false. An empty CharSequence (length()=0) will return false. 

         StringUtils.isAlphanumeric(null)   = false
 StringUtils.isAlphanumeric("")     = false
 StringUtils.isAlphanumeric("  ")   = false
 StringUtils.isAlphanumeric("abc")  = true
 StringUtils.isAlphanumeric("ab c") = false
 StringUtils.isAlphanumeric("ab2c") = true
 StringUtils.isAlphanumeric("ab-c") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if only contains letters or digits, and is non-null
        Since:
        3.0 Changed signature from isAlphanumeric(String) to isAlphanumeric(CharSequence), 3.0 Changed "" to return false and not true

      • isAlphanumericSpace

        public static boolean isAlphanumericSpace​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only Unicode letters, digits or space (' ').

        null will return false. An empty CharSequence (length()=0) will return true. 

         StringUtils.isAlphanumericSpace(null)   = false
 StringUtils.isAlphanumericSpace("")     = true
 StringUtils.isAlphanumericSpace("  ")   = true
 StringUtils.isAlphanumericSpace("abc")  = true
 StringUtils.isAlphanumericSpace("ab c") = true
 StringUtils.isAlphanumericSpace("ab2c") = true
 StringUtils.isAlphanumericSpace("ab-c") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if only contains letters, digits or space, and is non-null
        Since:
        3.0 Changed signature from isAlphanumericSpace(String) to isAlphanumericSpace(CharSequence)

      • isAlphaSpace

        public static boolean isAlphaSpace​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only Unicode letters and space (' ').

        null will return false An empty CharSequence (length()=0) will return true. 

         StringUtils.isAlphaSpace(null)   = false
 StringUtils.isAlphaSpace("")     = true
 StringUtils.isAlphaSpace("  ")   = true
 StringUtils.isAlphaSpace("abc")  = true
 StringUtils.isAlphaSpace("ab c") = true
 StringUtils.isAlphaSpace("ab2c") = false
 StringUtils.isAlphaSpace("ab-c") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if only contains letters and space, and is non-null
        Since:
        3.0 Changed signature from isAlphaSpace(String) to isAlphaSpace(CharSequence)

      • isAnyBlank

        public static boolean isAnyBlank​(java.lang.CharSequence... css)

        Checks if any of the CharSequences are empty ("") or null or whitespace only.

        Whitespace is defined by Character.isWhitespace(char). 

         StringUtils.isAnyBlank((String) null)    = true
 StringUtils.isAnyBlank((String[]) null)  = false
 StringUtils.isAnyBlank(null, "foo")      = true
 StringUtils.isAnyBlank(null, null)       = true
 StringUtils.isAnyBlank("", "bar")        = true
 StringUtils.isAnyBlank("bob", "")        = true
 StringUtils.isAnyBlank("  bob  ", null)  = true
 StringUtils.isAnyBlank(" ", "bar")       = true
 StringUtils.isAnyBlank(new String[] {})  = false
 StringUtils.isAnyBlank(new String[]{""}) = true
 StringUtils.isAnyBlank("foo", "bar")     = false
        Parameters:
        css - the CharSequences to check, may be null or empty
        Returns:
        true if any of the CharSequences are empty or null or whitespace only
        Since:
        3.2

      • isAnyEmpty

        public static boolean isAnyEmpty​(java.lang.CharSequence... css)

        Checks if any of the CharSequences are empty ("") or null. 

         StringUtils.isAnyEmpty((String) null)    = true
 StringUtils.isAnyEmpty((String[]) null)  = false
 StringUtils.isAnyEmpty(null, "foo")      = true
 StringUtils.isAnyEmpty("", "bar")        = true
 StringUtils.isAnyEmpty("bob", "")        = true
 StringUtils.isAnyEmpty("  bob  ", null)  = true
 StringUtils.isAnyEmpty(" ", "bar")       = false
 StringUtils.isAnyEmpty("foo", "bar")     = false
 StringUtils.isAnyEmpty(new String[]{})   = false
 StringUtils.isAnyEmpty(new String[]{""}) = true
        Parameters:
        css - the CharSequences to check, may be null or empty
        Returns:
        true if any of the CharSequences are empty or null
        Since:
        3.2

      • isAsciiPrintable

        public static boolean isAsciiPrintable​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only ASCII printable characters.

        null will return false. An empty CharSequence (length()=0) will return true. 

         StringUtils.isAsciiPrintable(null)     = false
 StringUtils.isAsciiPrintable("")       = true
 StringUtils.isAsciiPrintable(" ")      = true
 StringUtils.isAsciiPrintable("Ceki")   = true
 StringUtils.isAsciiPrintable("ab2c")   = true
 StringUtils.isAsciiPrintable("!ab-c~") = true
 StringUtils.isAsciiPrintable(" ") = true
 StringUtils.isAsciiPrintable("!") = true
 StringUtils.isAsciiPrintable("~") = true
 StringUtils.isAsciiPrintable("") = false
 StringUtils.isAsciiPrintable("Ceki Gülcü") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if every character is in the range 32 thru 126
        Since:
        2.1, 3.0 Changed signature from isAsciiPrintable(String) to isAsciiPrintable(CharSequence)

      • isBlank

        public static boolean isBlank​(java.lang.CharSequence cs)

        Checks if a CharSequence is empty (""), null or whitespace only.

        Whitespace is defined by Character.isWhitespace(char). 

         StringUtils.isBlank(null)      = true
 StringUtils.isBlank("")        = true
 StringUtils.isBlank(" ")       = true
 StringUtils.isBlank("bob")     = false
 StringUtils.isBlank("  bob  ") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if the CharSequence is null, empty or whitespace only
        Since:
        2.0, 3.0 Changed signature from isBlank(String) to isBlank(CharSequence)

      • isEmpty

        public static boolean isEmpty​(java.lang.CharSequence cs)

        Checks if a CharSequence is empty ("") or null. 

         StringUtils.isEmpty(null)      = true
 StringUtils.isEmpty("")        = true
 StringUtils.isEmpty(" ")       = false
 StringUtils.isEmpty("bob")     = false
 StringUtils.isEmpty("  bob  ") = false

        NOTE: This method changed in Lang version 2.0. It no longer trims the CharSequence. That functionality is available in isBlank().

        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if the CharSequence is empty or null
        Since:
        3.0 Changed signature from isEmpty(String) to isEmpty(CharSequence)

      • isMixedCase

        public static boolean isMixedCase​(java.lang.CharSequence cs)

        Checks if the CharSequence contains mixed casing of both uppercase and lowercase characters.

        null will return false. An empty CharSequence (length()=0) will return false. 

         StringUtils.isMixedCase(null)    = false
 StringUtils.isMixedCase("")      = false
 StringUtils.isMixedCase("ABC")   = false
 StringUtils.isMixedCase("abc")   = false
 StringUtils.isMixedCase("aBc")   = true
 StringUtils.isMixedCase("A c")   = true
 StringUtils.isMixedCase("A1c")   = true
 StringUtils.isMixedCase("a/C")   = true
 StringUtils.isMixedCase("aC\t")  = true
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if the CharSequence contains both uppercase and lowercase characters
        Since:
        3.5

      • isNoneBlank

        public static boolean isNoneBlank​(java.lang.CharSequence... css)

        Checks if none of the CharSequences are empty (""), null or whitespace only.

        Whitespace is defined by Character.isWhitespace(char). 

         StringUtils.isNoneBlank((String) null)    = false
 StringUtils.isNoneBlank((String[]) null)  = true
 StringUtils.isNoneBlank(null, "foo")      = false
 StringUtils.isNoneBlank(null, null)       = false
 StringUtils.isNoneBlank("", "bar")        = false
 StringUtils.isNoneBlank("bob", "")        = false
 StringUtils.isNoneBlank("  bob  ", null)  = false
 StringUtils.isNoneBlank(" ", "bar")       = false
 StringUtils.isNoneBlank(new String[] {})  = true
 StringUtils.isNoneBlank(new String[]{""}) = false
 StringUtils.isNoneBlank("foo", "bar")     = true
        Parameters:
        css - the CharSequences to check, may be null or empty
        Returns:
        true if none of the CharSequences are empty or null or whitespace only
        Since:
        3.2

      • isNoneEmpty

        public static boolean isNoneEmpty​(java.lang.CharSequence... css)

        Checks if none of the CharSequences are empty ("") or null. 

         StringUtils.isNoneEmpty((String) null)    = false
 StringUtils.isNoneEmpty((String[]) null)  = true
 StringUtils.isNoneEmpty(null, "foo")      = false
 StringUtils.isNoneEmpty("", "bar")        = false
 StringUtils.isNoneEmpty("bob", "")        = false
 StringUtils.isNoneEmpty("  bob  ", null)  = false
 StringUtils.isNoneEmpty(new String[] {})  = true
 StringUtils.isNoneEmpty(new String[]{""}) = false
 StringUtils.isNoneEmpty(" ", "bar")       = true
 StringUtils.isNoneEmpty("foo", "bar")     = true
        Parameters:
        css - the CharSequences to check, may be null or empty
        Returns:
        true if none of the CharSequences are empty or null
        Since:
        3.2

      • isNotBlank

        public static boolean isNotBlank​(java.lang.CharSequence cs)

        Checks if a CharSequence is not empty (""), not null and not whitespace only.

        Whitespace is defined by Character.isWhitespace(char). 

         StringUtils.isNotBlank(null)      = false
 StringUtils.isNotBlank("")        = false
 StringUtils.isNotBlank(" ")       = false
 StringUtils.isNotBlank("bob")     = true
 StringUtils.isNotBlank("  bob  ") = true
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if the CharSequence is not empty and not null and not whitespace only
        Since:
        2.0, 3.0 Changed signature from isNotBlank(String) to isNotBlank(CharSequence)

      • isNotEmpty

        public static boolean isNotEmpty​(java.lang.CharSequence cs)

        Checks if a CharSequence is not empty ("") and not null. 

         StringUtils.isNotEmpty(null)      = false
 StringUtils.isNotEmpty("")        = false
 StringUtils.isNotEmpty(" ")       = true
 StringUtils.isNotEmpty("bob")     = true
 StringUtils.isNotEmpty("  bob  ") = true
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if the CharSequence is not empty and not null
        Since:
        3.0 Changed signature from isNotEmpty(String) to isNotEmpty(CharSequence)

      • isNumeric

        public static boolean isNumeric​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only Unicode digits. A decimal point is not a Unicode digit and returns false.

        null will return false. An empty CharSequence (length()=0) will return false.

        Note that the method does not allow for a leading sign, either positive or negative. Also, if a String passes the numeric test, it may still generate a NumberFormatException when parsed by Integer.parseInt or Long.parseLong, e.g. if the value is outside the range for int or long respectively. 

         StringUtils.isNumeric(null)   = false
 StringUtils.isNumeric("")     = false
 StringUtils.isNumeric("  ")   = false
 StringUtils.isNumeric("123")  = true
 StringUtils.isNumeric("१२३")  = true
 StringUtils.isNumeric("12 3") = false
 StringUtils.isNumeric("ab2c") = false
 StringUtils.isNumeric("12-3") = false
 StringUtils.isNumeric("12.3") = false
 StringUtils.isNumeric("-123") = false
 StringUtils.isNumeric("+123") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if only contains digits, and is non-null
        Since:
        3.0 Changed signature from isNumeric(String) to isNumeric(CharSequence), 3.0 Changed "" to return false and not true

      • isNumericSpace

        public static boolean isNumericSpace​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only Unicode digits or space (' '). A decimal point is not a Unicode digit and returns false.

        null will return false. An empty CharSequence (length()=0) will return true. 

         StringUtils.isNumericSpace(null)   = false
 StringUtils.isNumericSpace("")     = true
 StringUtils.isNumericSpace("  ")   = true
 StringUtils.isNumericSpace("123")  = true
 StringUtils.isNumericSpace("12 3") = true
 StringUtils.isNumericSpace("१२३")  = true
 StringUtils.isNumericSpace("१२ ३")  = true
 StringUtils.isNumericSpace("ab2c") = false
 StringUtils.isNumericSpace("12-3") = false
 StringUtils.isNumericSpace("12.3") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if only contains digits or space, and is non-null
        Since:
        3.0 Changed signature from isNumericSpace(String) to isNumericSpace(CharSequence)

      • isWhitespace

        public static boolean isWhitespace​(java.lang.CharSequence cs)

        Checks if the CharSequence contains only whitespace.

        Whitespace is defined by Character.isWhitespace(char).

        null will return false. An empty CharSequence (length()=0) will return true. 

         StringUtils.isWhitespace(null)   = false
 StringUtils.isWhitespace("")     = true
 StringUtils.isWhitespace("  ")   = true
 StringUtils.isWhitespace("abc")  = false
 StringUtils.isWhitespace("ab2c") = false
 StringUtils.isWhitespace("ab-c") = false
        Parameters:
        cs - the CharSequence to check, may be null
        Returns:
        true if only contains whitespace, and is non-null
        Since:
        2.0, 3.0 Changed signature from isWhitespace(String) to isWhitespace(CharSequence)

      • join

        public static java.lang.String join​(boolean[] array,
                                    char delimiter)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)              = null
 StringUtils.join([], *)                = ""
 StringUtils.join([null], *)            = ""
 StringUtils.join([false, false], ';')  = "false;false"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        Returns:
        the joined String, null if null array input
        Since:
        3.12.0

      • join

        public static java.lang.String join​(boolean[] array,
                                    char delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)                   = null
 StringUtils.join([], *)                     = ""
 StringUtils.join([null], *)                 = ""
 StringUtils.join([true, false, true], ';')  = "true;false;true"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the array
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
        Returns:
        the joined String, null if null array input
        Since:
        3.12.0

      • join

        public static java.lang.String join​(byte[] array,
                                    char delimiter)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(byte[] array,
                                    char delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the array
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(char[] array,
                                    char delimiter)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(char[] array,
                                    char delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the array
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(double[] array,
                                    char delimiter)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(double[] array,
                                    char delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the array
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(float[] array,
                                    char delimiter)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(float[] array,
                                    char delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the array
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(int[] array,
                                    char separator)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        separator - the separator character to use
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(int[] array,
                                    char delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the array
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(java.lang.Iterable<?> iterable,
                                    char separator)

        Joins the elements of the provided Iterable into a single String containing the provided elements.

        No delimiter is added before or after the list. Null objects or empty strings within the iteration are represented by empty strings.

        See the examples here: join(Object[],char).

        Parameters:
        iterable - the Iterable providing the values to join together, may be null
        separator - the separator character to use
        Returns:
        the joined String, null if null iterator input
        Since:
        2.3

      • join

        public static java.lang.String join​(java.lang.Iterable<?> iterable,
                                    java.lang.String separator)

        Joins the elements of the provided Iterable into a single String containing the provided elements.

        No delimiter is added before or after the list. A null separator is the same as an empty String ("").

        See the examples here: join(Object[],String).

        Parameters:
        iterable - the Iterable providing the values to join together, may be null
        separator - the separator character to use, null treated as ""
        Returns:
        the joined String, null if null iterator input
        Since:
        2.3

      • join

        public static java.lang.String join​(java.util.Iterator<?> iterator,
                                    char separator)

        Joins the elements of the provided Iterator into a single String containing the provided elements.

        No delimiter is added before or after the list. Null objects or empty strings within the iteration are represented by empty strings.

        See the examples here: join(Object[],char).

        Parameters:
        iterator - the Iterator of values to join together, may be null
        separator - the separator character to use
        Returns:
        the joined String, null if null iterator input
        Since:
        2.0

      • join

        public static java.lang.String join​(java.util.Iterator<?> iterator,
                                    java.lang.String separator)

        Joins the elements of the provided Iterator into a single String containing the provided elements.

        No delimiter is added before or after the list. A null separator is the same as an empty String ("").

        See the examples here: join(Object[],String).

        Parameters:
        iterator - the Iterator of values to join together, may be null
        separator - the separator character to use, null treated as ""
        Returns:
        the joined String, null if null iterator input

      • join

        public static java.lang.String join​(java.util.List<?> list,
                                    char separator,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided List into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join(["a", "b", "c"], ';')  = "a;b;c"
 StringUtils.join(["a", "b", "c"], null) = "abc"
 StringUtils.join([null, "", "a"], ';')  = ";;a"
        Parameters:
        list - the List of values to join together, may be null
        separator - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the list
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the list
        Returns:
        the joined String, null if null list input
        Since:
        3.8

      • join

        public static java.lang.String join​(java.util.List<?> list,
                                    java.lang.String separator,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided List into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join(["a", "b", "c"], ';')  = "a;b;c"
 StringUtils.join(["a", "b", "c"], null) = "abc"
 StringUtils.join([null, "", "a"], ';')  = ";;a"
        Parameters:
        list - the List of values to join together, may be null
        separator - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the list
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the list
        Returns:
        the joined String, null if null list input
        Since:
        3.8

      • join

        public static java.lang.String join​(long[] array,
                                    char separator)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        separator - the separator character to use
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(long[] array,
                                    char delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the array
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(java.lang.Object[] array,
                                    char delimiter)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join(["a", "b", "c"], ';')  = "a;b;c"
 StringUtils.join(["a", "b", "c"], null) = "abc"
 StringUtils.join([null, "", "a"], ';')  = ";;a"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        Returns:
        the joined String, null if null array input
        Since:
        2.0

      • join

        public static java.lang.String join​(java.lang.Object[] array,
                                    char delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join(["a", "b", "c"], ';')  = "a;b;c"
 StringUtils.join(["a", "b", "c"], null) = "abc"
 StringUtils.join([null, "", "a"], ';')  = ";;a"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the array
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
        Returns:
        the joined String, null if null array input
        Since:
        2.0

      • join

        public static java.lang.String join​(java.lang.Object[] array,
                                    java.lang.String delimiter)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. A null separator is the same as an empty String (""). Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)                = null
 StringUtils.join([], *)                  = ""
 StringUtils.join([null], *)              = ""
 StringUtils.join(["a", "b", "c"], "--")  = "a--b--c"
 StringUtils.join(["a", "b", "c"], null)  = "abc"
 StringUtils.join(["a", "b", "c"], "")    = "abc"
 StringUtils.join([null, "", "a"], ',')   = ",,a"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use, null treated as ""
        Returns:
        the joined String, null if null array input

      • join

        public static java.lang.String join​(java.lang.Object[] array,
                                    java.lang.String delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. A null separator is the same as an empty String (""). Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *, *, *)                = null
 StringUtils.join([], *, *, *)                  = ""
 StringUtils.join([null], *, *, *)              = ""
 StringUtils.join(["a", "b", "c"], "--", 0, 3)  = "a--b--c"
 StringUtils.join(["a", "b", "c"], "--", 1, 3)  = "b--c"
 StringUtils.join(["a", "b", "c"], "--", 2, 3)  = "c"
 StringUtils.join(["a", "b", "c"], "--", 2, 2)  = ""
 StringUtils.join(["a", "b", "c"], null, 0, 3)  = "abc"
 StringUtils.join(["a", "b", "c"], "", 0, 3)    = "abc"
 StringUtils.join([null, "", "a"], ',', 0, 3)   = ",,a"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use, null treated as ""
        startIndex - the first index to start joining from.
        endIndex - the index to stop joining from (exclusive).
        Returns:
        the joined String, null if null array input; or the empty string if endIndex - startIndex <= 0. The number of joined entries is given by endIndex - startIndex
        Throws:
        java.lang.ArrayIndexOutOfBoundsException - ife
        startIndex < 0 or
        startIndex >= array.length() or
        endIndex < 0 or
        endIndex > array.length()

      • join

        public static java.lang.String join​(short[] array,
                                    char delimiter)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        public static java.lang.String join​(short[] array,
                                    char delimiter,
                                    int startIndex,
                                    int endIndex)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null, *)               = null
 StringUtils.join([], *)                 = ""
 StringUtils.join([null], *)             = ""
 StringUtils.join([1, 2, 3], ';')  = "1;2;3"
 StringUtils.join([1, 2, 3], null) = "123"
        Parameters:
        array - the array of values to join together, may be null
        delimiter - the separator character to use
        startIndex - the first index to start joining from. It is an error to pass in a start index past the end of the array
        endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
        Returns:
        the joined String, null if null array input
        Since:
        3.2

      • join

        @SafeVarargs
public static <T> java.lang.String join​(T... elements)

        Joins the elements of the provided array into a single String containing the provided list of elements.

        No separator is added to the joined String. Null objects or empty strings within the array are represented by empty strings. 

         StringUtils.join(null)            = null
 StringUtils.join([])              = ""
 StringUtils.join([null])          = ""
 StringUtils.join(["a", "b", "c"]) = "abc"
 StringUtils.join([null, "", "a"]) = "a"
        Type Parameters:
        T - the specific type of values to join together
        Parameters:
        elements - the values to join together, may be null
        Returns:
        the joined String, null if null array input
        Since:
        2.0, 3.0 Changed signature to use varargs

      • joinWith

        public static java.lang.String joinWith​(java.lang.String delimiter,
                                        java.lang.Object... array)

        Joins the elements of the provided varargs into a single String containing the provided elements.

        No delimiter is added before or after the list. null elements and separator are treated as empty Strings (""). 

         StringUtils.joinWith(",", {"a", "b"})        = "a,b"
 StringUtils.joinWith(",", {"a", "b",""})     = "a,b,"
 StringUtils.joinWith(",", {"a", null, "b"})  = "a,,b"
 StringUtils.joinWith(null, {"a", "b"})       = "ab"
        Parameters:
        delimiter - the separator character to use, null treated as ""
        array - the varargs providing the values to join together. null elements are treated as ""
        Returns:
        the joined String.
        Throws:
        java.lang.IllegalArgumentException - if a null varargs is provided
        Since:
        3.5

      • lastIndexOf

        public static int lastIndexOf​(java.lang.CharSequence seq,
                              java.lang.CharSequence searchSeq)

        Finds the last index within a CharSequence, handling null. This method uses String.lastIndexOf(String) if possible.

        A null CharSequence will return -1. 

         StringUtils.lastIndexOf(null, *)          = -1
 StringUtils.lastIndexOf(*, null)          = -1
 StringUtils.lastIndexOf("", "")           = 0
 StringUtils.lastIndexOf("aabaabaa", "a")  = 7
 StringUtils.lastIndexOf("aabaabaa", "b")  = 5
 StringUtils.lastIndexOf("aabaabaa", "ab") = 4
 StringUtils.lastIndexOf("aabaabaa", "")   = 8
        Parameters:
        seq - the CharSequence to check, may be null
        searchSeq - the CharSequence to find, may be null
        Returns:
        the last index of the search String, -1 if no match or null string input
        Since:
        2.0, 3.0 Changed signature from lastIndexOf(String, String) to lastIndexOf(CharSequence, CharSequence)

      • lastIndexOf

        public static int lastIndexOf​(java.lang.CharSequence seq,
                              java.lang.CharSequence searchSeq,
                              int startPos)

        Finds the last index within a CharSequence, handling null. This method uses String.lastIndexOf(String, int) if possible.

        A null CharSequence will return -1. A negative start position returns -1. An empty ("") search CharSequence always matches unless the start position is negative. A start position greater than the string length searches the whole string. The search starts at the startPos and works backwards; matches starting after the start position are ignored. 

         StringUtils.lastIndexOf(null, *, *)          = -1
 StringUtils.lastIndexOf(*, null, *)          = -1
 StringUtils.lastIndexOf("aabaabaa", "a", 8)  = 7
 StringUtils.lastIndexOf("aabaabaa", "b", 8)  = 5
 StringUtils.lastIndexOf("aabaabaa", "ab", 8) = 4
 StringUtils.lastIndexOf("aabaabaa", "b", 9)  = 5
 StringUtils.lastIndexOf("aabaabaa", "b", -1) = -1
 StringUtils.lastIndexOf("aabaabaa", "a", 0)  = 0
 StringUtils.lastIndexOf("aabaabaa", "b", 0)  = -1
 StringUtils.lastIndexOf("aabaabaa", "b", 1)  = -1
 StringUtils.lastIndexOf("aabaabaa", "b", 2)  = 2
 StringUtils.lastIndexOf("aabaabaa", "ba", 2)  = 2
        Parameters:
        seq - the CharSequence to check, may be null
        searchSeq - the CharSequence to find, may be null
        startPos - the start position, negative treated as zero
        Returns:
        the last index of the search CharSequence (always ≤ startPos), -1 if no match or null string input
        Since:
        2.0, 3.0 Changed signature from lastIndexOf(String, String, int) to lastIndexOf(CharSequence, CharSequence, int)

      • lastIndexOf

        public static int lastIndexOf​(java.lang.CharSequence seq,
                              int searchChar)
        Returns the index within seq of the last occurrence of the specified character. For values of searchChar in the range from 0 to 0xFFFF (inclusive), the index (in Unicode code units) returned is the largest value k such that: 
         this.charAt(k) == searchChar
        is true. For other values of searchChar, it is the largest value k such that: 
         this.codePointAt(k) == searchChar
        is true. In either case, if no such character occurs in this string, then -1 is returned. Furthermore, a null or empty ("") CharSequence will return -1. The seq CharSequence object is searched backwards starting at the last character. 
         StringUtils.lastIndexOf(null, *)         = -1
 StringUtils.lastIndexOf("", *)           = -1
 StringUtils.lastIndexOf("aabaabaa", 'a') = 7
 StringUtils.lastIndexOf("aabaabaa", 'b') = 5
        Parameters:
        seq - the CharSequence to check, may be null
        searchChar - the character to find
        Returns:
        the last index of the search character, -1 if no match or null string input
        Since:
        2.0, 3.0 Changed signature from lastIndexOf(String, int) to lastIndexOf(CharSequence, int), 3.6 Updated CharSequenceUtils call to behave more like String

      • lastIndexOf

        public static int lastIndexOf​(java.lang.CharSequence seq,
                              int searchChar,
                              int startPos)
        Returns the index within seq of the last occurrence of the specified character, searching backward starting at the specified index. For values of searchChar in the range from 0 to 0xFFFF (inclusive), the index returned is the largest value k such that: 
         (this.charAt(k) == searchChar) && (k <= startPos)
        is true. For other values of searchChar, it is the largest value k such that: 
         (this.codePointAt(k) == searchChar) && (k <= startPos)
        is true. In either case, if no such character occurs in seq at or before position startPos, then -1 is returned. Furthermore, a null or empty ("") CharSequence will return -1. A start position greater than the string length searches the whole string. The search starts at the startPos and works backwards; matches starting after the start position are ignored.

        All indices are specified in char values (Unicode code units). 

         StringUtils.lastIndexOf(null, *, *)          = -1
 StringUtils.lastIndexOf("", *,  *)           = -1
 StringUtils.lastIndexOf("aabaabaa", 'b', 8)  = 5
 StringUtils.lastIndexOf("aabaabaa", 'b', 4)  = 2
 StringUtils.lastIndexOf("aabaabaa", 'b', 0)  = -1
 StringUtils.lastIndexOf("aabaabaa", 'b', 9)  = 5
 StringUtils.lastIndexOf("aabaabaa", 'b', -1) = -1
 StringUtils.lastIndexOf("aabaabaa", 'a', 0)  = 0
        Parameters:
        seq - the CharSequence to check, may be null
        searchChar - the character to find
        startPos - the start position
        Returns:
        the last index of the search character (always ≤ startPos), -1 if no match or null string input
        Since:
        2.0, 3.0 Changed signature from lastIndexOf(String, int, int) to lastIndexOf(CharSequence, int, int)

      • lastIndexOfAny

        public static int lastIndexOfAny​(java.lang.CharSequence str,
                                 java.lang.CharSequence... searchStrs)

        Find the latest index of any substring in a set of potential substrings.

        A null CharSequence will return -1. A null search array will return -1. A null or zero length search array entry will be ignored, but a search array containing "" will return the length of str if str is not null. This method uses String.indexOf(String) if possible 

         StringUtils.lastIndexOfAny(null, *)                    = -1
 StringUtils.lastIndexOfAny(*, null)                    = -1
 StringUtils.lastIndexOfAny(*, [])                      = -1
 StringUtils.lastIndexOfAny(*, [null])                  = -1
 StringUtils.lastIndexOfAny("zzabyycdxx", ["ab", "cd"]) = 6
 StringUtils.lastIndexOfAny("zzabyycdxx", ["cd", "ab"]) = 6
 StringUtils.lastIndexOfAny("zzabyycdxx", ["mn", "op"]) = -1
 StringUtils.lastIndexOfAny("zzabyycdxx", ["mn", "op"]) = -1
 StringUtils.lastIndexOfAny("zzabyycdxx", ["mn", ""])   = 10
        Parameters:
        str - the CharSequence to check, may be null
        searchStrs - the CharSequences to search for, may be null
        Returns:
        the last index of any of the CharSequences, -1 if no match
        Since:
        3.0 Changed signature from lastIndexOfAny(String, String[]) to lastIndexOfAny(CharSequence, CharSequence)

      • lastIndexOfIgnoreCase

        public static int lastIndexOfIgnoreCase​(java.lang.CharSequence str,
                                        java.lang.CharSequence searchStr)

        Case in-sensitive find of the last index within a CharSequence.

        A null CharSequence will return -1. A negative start position returns -1. An empty ("") search CharSequence always matches unless the start position is negative. A start position greater than the string length searches the whole string. 

         StringUtils.lastIndexOfIgnoreCase(null, *)          = -1
 StringUtils.lastIndexOfIgnoreCase(*, null)          = -1
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A")  = 7
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B")  = 5
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB") = 4
        Parameters:
        str - the CharSequence to check, may be null
        searchStr - the CharSequence to find, may be null
        Returns:
        the first index of the search CharSequence, -1 if no match or null string input
        Since:
        2.5, 3.0 Changed signature from lastIndexOfIgnoreCase(String, String) to lastIndexOfIgnoreCase(CharSequence, CharSequence)

      • lastIndexOfIgnoreCase

        public static int lastIndexOfIgnoreCase​(java.lang.CharSequence str,
                                        java.lang.CharSequence searchStr,
                                        int startPos)

        Case in-sensitive find of the last index within a CharSequence from the specified position.

        A null CharSequence will return -1. A negative start position returns -1. An empty ("") search CharSequence always matches unless the start position is negative. A start position greater than the string length searches the whole string. The search starts at the startPos and works backwards; matches starting after the start position are ignored. 

         StringUtils.lastIndexOfIgnoreCase(null, *, *)          = -1
 StringUtils.lastIndexOfIgnoreCase(*, null, *)          = -1
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 8)  = 7
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 8)  = 5
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB", 8) = 4
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 9)  = 5
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", -1) = -1
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 0)  = 0
 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 0)  = -1
        Parameters:
        str - the CharSequence to check, may be null
        searchStr - the CharSequence to find, may be null
        startPos - the start position
        Returns:
        the last index of the search CharSequence (always ≤ startPos), -1 if no match or null input
        Since:
        2.5, 3.0 Changed signature from lastIndexOfIgnoreCase(String, String, int) to lastIndexOfIgnoreCase(CharSequence, CharSequence, int)

      • lastOrdinalIndexOf

        public static int lastOrdinalIndexOf​(java.lang.CharSequence str,
                                     java.lang.CharSequence searchStr,
                                     int ordinal)

        Finds the n-th last index within a String, handling null. This method uses String.lastIndexOf(String).

        A null String will return -1. 

         StringUtils.lastOrdinalIndexOf(null, *, *)          = -1
 StringUtils.lastOrdinalIndexOf(*, null, *)          = -1
 StringUtils.lastOrdinalIndexOf("", "", *)           = 0
 StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 1)  = 7
 StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 2)  = 6
 StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 1)  = 5
 StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 2)  = 2
 StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 1) = 4
 StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 2) = 1
 StringUtils.lastOrdinalIndexOf("aabaabaa", "", 1)   = 8
 StringUtils.lastOrdinalIndexOf("aabaabaa", "", 2)   = 8

        Note that 'tail(CharSequence str, int n)' may be implemented as: 

         str.substring(lastOrdinalIndexOf(str, "\n", n) + 1)
        Parameters:
        str - the CharSequence to check, may be null
        searchStr - the CharSequence to find, may be null
        ordinal - the n-th last searchStr to find
        Returns:
        the n-th last index of the search CharSequence, -1 (INDEX_NOT_FOUND) if no match or null string input
        Since:
        2.5, 3.0 Changed signature from lastOrdinalIndexOf(String, String, int) to lastOrdinalIndexOf(CharSequence, CharSequence, int)

      • left

        public static java.lang.String left​(java.lang.String str,
                                    int len)

        Gets the leftmost len characters of a String.

        If len characters are not available, or the String is null, the String will be returned without an exception. An empty String is returned if len is negative. 

         StringUtils.left(null, *)    = null
 StringUtils.left(*, -ve)     = ""
 StringUtils.left("", *)      = ""
 StringUtils.left("abc", 0)   = ""
 StringUtils.left("abc", 2)   = "ab"
 StringUtils.left("abc", 4)   = "abc"
        Parameters:
        str - the String to get the leftmost characters from, may be null
        len - the length of the required String
        Returns:
        the leftmost characters, null if null String input

      • leftPad

        public static java.lang.String leftPad​(java.lang.String str,
                                       int size)

        Left pad a String with spaces (' ').

        The String is padded to the size of size. 

         StringUtils.leftPad(null, *)   = null
 StringUtils.leftPad("", 3)     = "   "
 StringUtils.leftPad("bat", 3)  = "bat"
 StringUtils.leftPad("bat", 5)  = "  bat"
 StringUtils.leftPad("bat", 1)  = "bat"
 StringUtils.leftPad("bat", -1) = "bat"
        Parameters:
        str - the String to pad out, may be null
        size - the size to pad to
        Returns:
        left padded String or original String if no padding is necessary, null if null String input

      • leftPad

        public static java.lang.String leftPad​(java.lang.String str,
                                       int size,
                                       char padChar)

        Left pad a String with a specified character.

        Pad to a size of size. 

         StringUtils.leftPad(null, *, *)     = null
 StringUtils.leftPad("", 3, 'z')     = "zzz"
 StringUtils.leftPad("bat", 3, 'z')  = "bat"
 StringUtils.leftPad("bat", 5, 'z')  = "zzbat"
 StringUtils.leftPad("bat", 1, 'z')  = "bat"
 StringUtils.leftPad("bat", -1, 'z') = "bat"
        Parameters:
        str - the String to pad out, may be null
        size - the size to pad to
        padChar - the character to pad with
        Returns:
        left padded String or original String if no padding is necessary, null if null String input
        Since:
        2.0

      • leftPad

        public static java.lang.String leftPad​(java.lang.String str,
                                       int size,
                                       java.lang.String padStr)

        Left pad a String with a specified String.

        Pad to a size of size. 

         StringUtils.leftPad(null, *, *)      = null
 StringUtils.leftPad("", 3, "z")      = "zzz"
 StringUtils.leftPad("bat", 3, "yz")  = "bat"
 StringUtils.leftPad("bat", 5, "yz")  = "yzbat"
 StringUtils.leftPad("bat", 8, "yz")  = "yzyzybat"
 StringUtils.leftPad("bat", 1, "yz")  = "bat"
 StringUtils.leftPad("bat", -1, "yz") = "bat"
 StringUtils.leftPad("bat", 5, null)  = "  bat"
 StringUtils.leftPad("bat", 5, "")    = "  bat"
        Parameters:
        str - the String to pad out, may be null
        size - the size to pad to
        padStr - the String to pad with, null or empty treated as single space
        Returns:
        left padded String or original String if no padding is necessary, null if null String input

      • length

        public static int length​(java.lang.CharSequence cs)
        Gets a CharSequence length or 0 if the CharSequence is null.
        Parameters:
        cs - a CharSequence or null
        Returns:
        CharSequence length or 0 if the CharSequence is null.
        Since:
        2.4, 3.0 Changed signature from length(String) to length(CharSequence)

      • lowerCase

        public static java.lang.String lowerCase​(java.lang.String str)

        Converts a String to lower case as per String.toLowerCase().

        A null input String returns null. 

         StringUtils.lowerCase(null)  = null
 StringUtils.lowerCase("")    = ""
 StringUtils.lowerCase("aBc") = "abc"

        Note: As described in the documentation for String.toLowerCase(), the result of this method is affected by the current locale. For platform-independent case transformations, the method lowerCase(String, Locale) should be used with a specific locale (e.g. Locale.ENGLISH).

        Parameters:
        str - the String to lower case, may be null
        Returns:
        the lower cased String, null if null String input

      • lowerCase

        public static java.lang.String lowerCase​(java.lang.String str,
                                         java.util.Locale locale)

        Converts a String to lower case as per String.toLowerCase(Locale).

        A null input String returns null. 

         StringUtils.lowerCase(null, Locale.ENGLISH)  = null
 StringUtils.lowerCase("", Locale.ENGLISH)    = ""
 StringUtils.lowerCase("aBc", Locale.ENGLISH) = "abc"
        Parameters:
        str - the String to lower case, may be null
        locale - the locale that defines the case transformation rules, must not be null
        Returns:
        the lower cased String, null if null String input
        Since:
        2.5

      • mid

        public static java.lang.String mid​(java.lang.String str,
                                   int pos,
                                   int len)

        Gets len characters from the middle of a String.

        If len characters are not available, the remainder of the String will be returned without an exception. If the String is null, null will be returned. An empty String is returned if len is negative or exceeds the length of str. 

         StringUtils.mid(null, *, *)    = null
 StringUtils.mid(*, *, -ve)     = ""
 StringUtils.mid("", 0, *)      = ""
 StringUtils.mid("abc", 0, 2)   = "ab"
 StringUtils.mid("abc", 0, 4)   = "abc"
 StringUtils.mid("abc", 2, 4)   = "c"
 StringUtils.mid("abc", 4, 2)   = ""
 StringUtils.mid("abc", -2, 2)  = "ab"
        Parameters:
        str - the String to get the characters from, may be null
        pos - the position to start from, negative treated as zero
        len - the length of the required String
        Returns:
        the middle characters, null if null String input

      • normalizeSpace

        public static java.lang.String normalizeSpace​(java.lang.String str)

        Similar to http://www.w3.org/TR/xpath/#function-normalize -space

        The function returns the argument string with whitespace normalized by using {@link #trim(String)} to remove leading and trailing whitespace and then replacing sequences of whitespace characters by a single space.

        In XML Whitespace characters are the same as those allowed by the S production, which is S ::= (#x20 | #x9 | #xD | #xA)+

        Java's regexp pattern \s defines whitespace as [ \t\n\x0B\f\r]

        For reference:

        • \x0B = vertical tab
        • \f = #xC = form feed
        • #x20 = space
        • #x9 = \t
        • #xA = \n
        • #xD = \r

        The difference is that Java's whitespace includes vertical tab and form feed, which this functional will also normalize. Additionally {@link #trim(String)} removes control characters (char <= 32) from both ends of this String.

        Parameters:
        str - the source String to normalize whitespaces from, may be null
        Returns:
        the modified string with whitespace normalized, null if null String input
        Since:
        3.0
        See Also:
        Pattern, trim(String), http://www.w3.org/TR/xpath/#function-normalize-space

      • ordinalIndexOf

        public static int ordinalIndexOf​(java.lang.CharSequence str,
                                 java.lang.CharSequence searchStr,
                                 int ordinal)

        Finds the n-th index within a CharSequence, handling null. This method uses String.indexOf(String) if possible.

        Note: The code starts looking for a match at the start of the target, incrementing the starting index by one after each successful match (unless searchStr is an empty string in which case the position is never incremented and 0 is returned immediately). This means that matches may overlap.

        A null CharSequence will return -1. 

         StringUtils.ordinalIndexOf(null, *, *)          = -1
 StringUtils.ordinalIndexOf(*, null, *)          = -1
 StringUtils.ordinalIndexOf("", "", *)           = 0
 StringUtils.ordinalIndexOf("aabaabaa", "a", 1)  = 0
 StringUtils.ordinalIndexOf("aabaabaa", "a", 2)  = 1
 StringUtils.ordinalIndexOf("aabaabaa", "b", 1)  = 2
 StringUtils.ordinalIndexOf("aabaabaa", "b", 2)  = 5
 StringUtils.ordinalIndexOf("aabaabaa", "ab", 1) = 1
 StringUtils.ordinalIndexOf("aabaabaa", "ab", 2) = 4
 StringUtils.ordinalIndexOf("aabaabaa", "", 1)   = 0
 StringUtils.ordinalIndexOf("aabaabaa", "", 2)   = 0

        Matches may overlap: 

         StringUtils.ordinalIndexOf("ababab", "aba", 1)   = 0
 StringUtils.ordinalIndexOf("ababab", "aba", 2)   = 2
 StringUtils.ordinalIndexOf("ababab", "aba", 3)   = -1

 StringUtils.ordinalIndexOf("abababab", "abab", 1) = 0
 StringUtils.ordinalIndexOf("abababab", "abab", 2) = 2
 StringUtils.ordinalIndexOf("abababab", "abab", 3) = 4
 StringUtils.ordinalIndexOf("abababab", "abab", 4) = -1

        Note that 'head(CharSequence str, int n)' may be implemented as: 

         str.substring(0, lastOrdinalIndexOf(str, "\n", n))
        Parameters:
        str - the CharSequence to check, may be null
        searchStr - the CharSequence to find, may be null
        ordinal - the n-th searchStr to find
        Returns:
        the n-th index of the search CharSequence, -1 (INDEX_NOT_FOUND) if no match or null string input
        Since:
        2.1, 3.0 Changed signature from ordinalIndexOf(String, String, int) to ordinalIndexOf(CharSequence, CharSequence, int)

      • overlay

        public static java.lang.String overlay​(java.lang.String str,
                                       java.lang.String overlay,
                                       int start,
                                       int end)

        Overlays part of a String with another String.

        A null string input returns null. A negative index is treated as zero. An index greater than the string length is treated as the string length. The start index is always the smaller of the two indices. 

         StringUtils.overlay(null, *, *, *)            = null
 StringUtils.overlay("", "abc", 0, 0)          = "abc"
 StringUtils.overlay("abcdef", null, 2, 4)     = "abef"
 StringUtils.overlay("abcdef", "", 2, 4)       = "abef"
 StringUtils.overlay("abcdef", "", 4, 2)       = "abef"
 StringUtils.overlay("abcdef", "zzzz", 2, 4)   = "abzzzzef"
 StringUtils.overlay("abcdef", "zzzz", 4, 2)   = "abzzzzef"
 StringUtils.overlay("abcdef", "zzzz", -1, 4)  = "zzzzef"
 StringUtils.overlay("abcdef", "zzzz", 2, 8)   = "abzzzz"
 StringUtils.overlay("abcdef", "zzzz", -2, -3) = "zzzzabcdef"
 StringUtils.overlay("abcdef", "zzzz", 8, 10)  = "abcdefzzzz"
        Parameters:
        str - the String to do overlaying in, may be null
        overlay - the String to overlay, may be null
        start - the position to start overlaying at
        end - the position to stop overlaying before
        Returns:
        overlayed String, null if null String input
        Since:
        2.0

      • prependIfMissing

        public static java.lang.String prependIfMissing​(java.lang.String str,
                                                java.lang.CharSequence prefix,
                                                java.lang.CharSequence... prefixes)
        Prepends the prefix to the start of the string if the string does not already start with any of the prefixes. 
         StringUtils.prependIfMissing(null, null) = null
 StringUtils.prependIfMissing("abc", null) = "abc"
 StringUtils.prependIfMissing("", "xyz") = "xyz"
 StringUtils.prependIfMissing("abc", "xyz") = "xyzabc"
 StringUtils.prependIfMissing("xyzabc", "xyz") = "xyzabc"
 StringUtils.prependIfMissing("XYZabc", "xyz") = "xyzXYZabc"

        With additional prefixes, 

         StringUtils.prependIfMissing(null, null, null) = null
 StringUtils.prependIfMissing("abc", null, null) = "abc"
 StringUtils.prependIfMissing("", "xyz", null) = "xyz"
 StringUtils.prependIfMissing("abc", "xyz", new CharSequence[]{null}) = "xyzabc"
 StringUtils.prependIfMissing("abc", "xyz", "") = "abc"
 StringUtils.prependIfMissing("abc", "xyz", "mno") = "xyzabc"
 StringUtils.prependIfMissing("xyzabc", "xyz", "mno") = "xyzabc"
 StringUtils.prependIfMissing("mnoabc", "xyz", "mno") = "mnoabc"
 StringUtils.prependIfMissing("XYZabc", "xyz", "mno") = "xyzXYZabc"
 StringUtils.prependIfMissing("MNOabc", "xyz", "mno") = "xyzMNOabc"
        Parameters:
        str - The string.
        prefix - The prefix to prepend to the start of the string.
        prefixes - Additional prefixes that are valid.
        Returns:
        A new String if prefix was prepended, the same string otherwise.
        Since:
        3.2

      • prependIfMissingIgnoreCase

        public static java.lang.String prependIfMissingIgnoreCase​(java.lang.String str,
                                                          java.lang.CharSequence prefix,
                                                          java.lang.CharSequence... prefixes)
        Prepends the prefix to the start of the string if the string does not already start, case insensitive, with any of the prefixes. 
         StringUtils.prependIfMissingIgnoreCase(null, null) = null
 StringUtils.prependIfMissingIgnoreCase("abc", null) = "abc"
 StringUtils.prependIfMissingIgnoreCase("", "xyz") = "xyz"
 StringUtils.prependIfMissingIgnoreCase("abc", "xyz") = "xyzabc"
 StringUtils.prependIfMissingIgnoreCase("xyzabc", "xyz") = "xyzabc"
 StringUtils.prependIfMissingIgnoreCase("XYZabc", "xyz") = "XYZabc"

        With additional prefixes, 

         StringUtils.prependIfMissingIgnoreCase(null, null, null) = null
 StringUtils.prependIfMissingIgnoreCase("abc", null, null) = "abc"
 StringUtils.prependIfMissingIgnoreCase("", "xyz", null) = "xyz"
 StringUtils.prependIfMissingIgnoreCase("abc", "xyz", new CharSequence[]{null}) = "xyzabc"
 StringUtils.prependIfMissingIgnoreCase("abc", "xyz", "") = "abc"
 StringUtils.prependIfMissingIgnoreCase("abc", "xyz", "mno") = "xyzabc"
 StringUtils.prependIfMissingIgnoreCase("xyzabc", "xyz", "mno") = "xyzabc"
 StringUtils.prependIfMissingIgnoreCase("mnoabc", "xyz", "mno") = "mnoabc"
 StringUtils.prependIfMissingIgnoreCase("XYZabc", "xyz", "mno") = "XYZabc"
 StringUtils.prependIfMissingIgnoreCase("MNOabc", "xyz", "mno") = "MNOabc"
        Parameters:
        str - The string.
        prefix - The prefix to prepend to the start of the string.
        prefixes - Additional prefixes that are valid (optional).
        Returns:
        A new String if prefix was prepended, the same string otherwise.
        Since:
        3.2

      • remove

        public static java.lang.String remove​(java.lang.String str,
                                      char remove)

        Removes all occurrences of a character from within the source string.

        A null source string will return null. An empty ("") source string will return the empty string. 

         StringUtils.remove(null, *)       = null
 StringUtils.remove("", *)         = ""
 StringUtils.remove("queued", 'u') = "qeed"
 StringUtils.remove("queued", 'z') = "queued"
        Parameters:
        str - the source String to search, may be null
        remove - the char to search for and remove, may be null
        Returns:
        the substring with the char removed if found, null if null String input
        Since:
        2.1

      • remove

        public static java.lang.String remove​(java.lang.String str,
                                      java.lang.String remove)

        Removes all occurrences of a substring from within the source string.

        A null source string will return null. An empty ("") source string will return the empty string. A null remove string will return the source string. An empty ("") remove string will return the source string. 

         StringUtils.remove(null, *)        = null
 StringUtils.remove("", *)          = ""
 StringUtils.remove(*, null)        = *
 StringUtils.remove(*, "")          = *
 StringUtils.remove("queued", "ue") = "qd"
 StringUtils.remove("queued", "zz") = "queued"
        Parameters:
        str - the source String to search, may be null
        remove - the String to search for and remove, may be null
        Returns:
        the substring with the string removed if found, null if null String input
        Since:
        2.1

      • removeAll

        @Deprecated
public static java.lang.String removeAll​(java.lang.String text,
                                         java.lang.String regex)
        Deprecated.
        Moved to RegExUtils.

        Removes each substring of the text String that matches the given regular expression.

        This method is a null safe equivalent to:
        • text.replaceAll(regex, StringUtils.EMPTY)
        • Pattern.compile(regex).matcher(text).replaceAll(StringUtils.EMPTY)

        A null reference passed to this method is a no-op.

        Unlike in the removePattern(String, String) method, the Pattern.DOTALL option is NOT automatically added. To use the DOTALL option prepend "(?s)" to the regex. DOTALL is also known as single-line mode in Perl. 

         StringUtils.removeAll(null, *)      = null
 StringUtils.removeAll("any", (String) null)  = "any"
 StringUtils.removeAll("any", "")    = "any"
 StringUtils.removeAll("any", ".*")  = ""
 StringUtils.removeAll("any", ".+")  = ""
 StringUtils.removeAll("abc", ".?")  = ""
 StringUtils.removeAll("A<__>\n<__>B", "<.*>")      = "A\nB"
 StringUtils.removeAll("A<__>\n<__>B", "(?s)<.*>")  = "AB"
 StringUtils.removeAll("ABCabc123abc", "[a-z]")     = "ABC123"
        Parameters:
        text - text to remove from, may be null
        regex - the regular expression to which this string is to be matched
        Returns:
        the text with any removes processed, null if null String input
        Throws:
        java.util.regex.PatternSyntaxException - if the regular expression's syntax is invalid
        Since:
        3.5
        See Also:
        replaceAll(String, String, String), removePattern(String, String), String.replaceAll(String, String), Pattern, Pattern.DOTALL

      • removeEnd

        public static java.lang.String removeEnd​(java.lang.String str,
                                         java.lang.String remove)

        Removes a substring only if it is at the end of a source string, otherwise returns the source string.

        A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string. 

         StringUtils.removeEnd(null, *)      = null
 StringUtils.removeEnd("", *)        = ""
 StringUtils.removeEnd(*, null)      = *
 StringUtils.removeEnd("www.domain.com", ".com.")  = "www.domain.com"
 StringUtils.removeEnd("www.domain.com", ".com")   = "www.domain"
 StringUtils.removeEnd("www.domain.com", "domain") = "www.domain.com"
 StringUtils.removeEnd("abc", "")    = "abc"
        Parameters:
        str - the source String to search, may be null
        remove - the String to search for and remove, may be null
        Returns:
        the substring with the string removed if found, null if null String input
        Since:
        2.1

      • removeEndIgnoreCase

        public static java.lang.String removeEndIgnoreCase​(java.lang.String str,
                                                   java.lang.String remove)

        Case insensitive removal of a substring if it is at the end of a source string, otherwise returns the source string.

        A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string. 

         StringUtils.removeEndIgnoreCase(null, *)      = null
 StringUtils.removeEndIgnoreCase("", *)        = ""
 StringUtils.removeEndIgnoreCase(*, null)      = *
 StringUtils.removeEndIgnoreCase("www.domain.com", ".com.")  = "www.domain.com"
 StringUtils.removeEndIgnoreCase("www.domain.com", ".com")   = "www.domain"
 StringUtils.removeEndIgnoreCase("www.domain.com", "domain") = "www.domain.com"
 StringUtils.removeEndIgnoreCase("abc", "")    = "abc"
 StringUtils.removeEndIgnoreCase("www.domain.com", ".COM") = "www.domain")
 StringUtils.removeEndIgnoreCase("www.domain.COM", ".com") = "www.domain")
        Parameters:
        str - the source String to search, may be null
        remove - the String to search for (case insensitive) and remove, may be null
        Returns:
        the substring with the string removed if found, null if null String input
        Since:
        2.4

      • removeFirst

        @Deprecated
public static java.lang.String removeFirst​(java.lang.String text,
                                           java.lang.String regex)
        Deprecated.
        Moved to RegExUtils.

        Removes the first substring of the text string that matches the given regular expression.

        This method is a null safe equivalent to:
        • text.replaceFirst(regex, StringUtils.EMPTY)
        • Pattern.compile(regex).matcher(text).replaceFirst(StringUtils.EMPTY)

        A null reference passed to this method is a no-op.

        The Pattern.DOTALL option is NOT automatically added. To use the DOTALL option prepend "(?s)" to the regex. DOTALL is also known as single-line mode in Perl. 

         StringUtils.removeFirst(null, *)      = null
 StringUtils.removeFirst("any", (String) null)  = "any"
 StringUtils.removeFirst("any", "")    = "any"
 StringUtils.removeFirst("any", ".*")  = ""
 StringUtils.removeFirst("any", ".+")  = ""
 StringUtils.removeFirst("abc", ".?")  = "bc"
 StringUtils.removeFirst("A<__>\n<__>B", "<.*>")      = "A\n<__>B"
 StringUtils.removeFirst("A<__>\n<__>B", "(?s)<.*>")  = "AB"
 StringUtils.removeFirst("ABCabc123", "[a-z]")          = "ABCbc123"
 StringUtils.removeFirst("ABCabc123abc", "[a-z]+")      = "ABC123abc"
        Parameters:
        text - text to remove from, may be null
        regex - the regular expression to which this string is to be matched
        Returns:
        the text with the first replacement processed, null if null String input
        Throws:
        java.util.regex.PatternSyntaxException - if the regular expression's syntax is invalid
        Since:
        3.5
        See Also:
        replaceFirst(String, String, String), String.replaceFirst(String, String), Pattern, Pattern.DOTALL

      • removeIgnoreCase

        public static java.lang.String removeIgnoreCase​(java.lang.String str,
                                                java.lang.String remove)

        Case insensitive removal of all occurrences of a substring from within the source string.

        A null source string will return null. An empty ("") source string will return the empty string. A null remove string will return the source string. An empty ("") remove string will return the source string. 

         StringUtils.removeIgnoreCase(null, *)        = null
 StringUtils.removeIgnoreCase("", *)          = ""
 StringUtils.removeIgnoreCase(*, null)        = *
 StringUtils.removeIgnoreCase(*, "")          = *
 StringUtils.removeIgnoreCase("queued", "ue") = "qd"
 StringUtils.removeIgnoreCase("queued", "zz") = "queued"
 StringUtils.removeIgnoreCase("quEUed", "UE") = "qd"
 StringUtils.removeIgnoreCase("queued", "zZ") = "queued"
        Parameters:
        str - the source String to search, may be null
        remove - the String to search for (case insensitive) and remove, may be null
        Returns:
        the substring with the string removed if found, null if null String input
        Since:
        3.5

      • removePattern

        @Deprecated
public static java.lang.String removePattern​(java.lang.String source,
                                             java.lang.String regex)
        Deprecated.
        Moved to RegExUtils.

        Removes each substring of the source String that matches the given regular expression using the DOTALL option.

        This call is a null safe equivalent to:
        • source.replaceAll(&quot;(?s)&quot; + regex, StringUtils.EMPTY)
        • Pattern.compile(regex, Pattern.DOTALL).matcher(source).replaceAll(StringUtils.EMPTY)

        A null reference passed to this method is a no-op. 

         StringUtils.removePattern(null, *)       = null
 StringUtils.removePattern("any", (String) null)   = "any"
 StringUtils.removePattern("A<__>\n<__>B", "<.*>")  = "AB"
 StringUtils.removePattern("ABCabc123", "[a-z]")    = "ABC123"
        Parameters:
        source - the source string
        regex - the regular expression to which this string is to be matched
        Returns:
        The resulting String
        Since:
        3.2, 3.5 Changed null reference passed to this method is a no-op.
        See Also:
        replacePattern(String, String, String), String.replaceAll(String, String), Pattern.DOTALL

      • removeStart

        public static java.lang.String removeStart​(java.lang.String str,
                                           java.lang.String remove)

        Removes a substring only if it is at the beginning of a source string, otherwise returns the source string.

        A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string. 

         StringUtils.removeStart(null, *)      = null
 StringUtils.removeStart("", *)        = ""
 StringUtils.removeStart(*, null)      = *
 StringUtils.removeStart("www.domain.com", "www.")   = "domain.com"
 StringUtils.removeStart("domain.com", "www.")       = "domain.com"
 StringUtils.removeStart("www.domain.com", "domain") = "www.domain.com"
 StringUtils.removeStart("abc", "")    = "abc"
        Parameters:
        str - the source String to search, may be null
        remove - the String to search for and remove, may be null
        Returns:
        the substring with the string removed if found, null if null String input
        Since:
        2.1

      • removeStartIgnoreCase

        public static java.lang.String removeStartIgnoreCase​(java.lang.String str,
                                                     java.lang.String remove)

        Case insensitive removal of a substring if it is at the beginning of a source string, otherwise returns the source string.

        A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string. 

         StringUtils.removeStartIgnoreCase(null, *)      = null
 StringUtils.removeStartIgnoreCase("", *)        = ""
 StringUtils.removeStartIgnoreCase(*, null)      = *
 StringUtils.removeStartIgnoreCase("www.domain.com", "www.")   = "domain.com"
 StringUtils.removeStartIgnoreCase("www.domain.com", "WWW.")   = "domain.com"
 StringUtils.removeStartIgnoreCase("domain.com", "www.")       = "domain.com"
 StringUtils.removeStartIgnoreCase("www.domain.com", "domain") = "www.domain.com"
 StringUtils.removeStartIgnoreCase("abc", "")    = "abc"
        Parameters:
        str - the source String to search, may be null
        remove - the String to search for (case insensitive) and remove, may be null
        Returns:
        the substring with the string removed if found, null if null String input
        Since:
        2.4

      • repeat

        public static java.lang.String repeat​(char ch,
                                      int repeat)

        Returns padding using the specified delimiter repeated to a given length. 

         StringUtils.repeat('e', 0)  = ""
 StringUtils.repeat('e', 3)  = "eee"
 StringUtils.repeat('e', -2) = ""

        Note: this method does not support padding with Unicode Supplementary Characters as they require a pair of chars to be represented. If you are needing to support full I18N of your applications consider using repeat(String, int) instead.

        Parameters:
        ch - character to repeat
        repeat - number of times to repeat char, negative treated as zero
        Returns:
        String with repeated character
        See Also:
        repeat(String, int)

      • repeat

        public static java.lang.String repeat​(java.lang.String str,
                                      int repeat)

        Repeat a String repeat times to form a new String. 

         StringUtils.repeat(null, 2) = null
 StringUtils.repeat("", 0)   = ""
 StringUtils.repeat("", 2)   = ""
 StringUtils.repeat("a", 3)  = "aaa"
 StringUtils.repeat("ab", 2) = "abab"
 StringUtils.repeat("a", -2) = ""
        Parameters:
        str - the String to repeat, may be null
        repeat - number of times to repeat str, negative treated as zero
        Returns:
        a new String consisting of the original String repeated, null if null String input

      • repeat

        public static java.lang.String repeat​(java.lang.String str,
                                      java.lang.String separator,
                                      int repeat)

        Repeat a String repeat times to form a new String, with a String separator injected each time. 

         StringUtils.repeat(null, null, 2) = null
 StringUtils.repeat(null, "x", 2)  = null
 StringUtils.repeat("", null, 0)   = ""
 StringUtils.repeat("", "", 2)     = ""
 StringUtils.repeat("", "x", 3)    = "xxx"
 StringUtils.repeat("?", ", ", 3)  = "?, ?, ?"
        Parameters:
        str - the String to repeat, may be null
        separator - the String to inject, may be null
        repeat - number of times to repeat str, negative treated as zero
        Returns:
        a new String consisting of the original String repeated, null if null String input
        Since:
        2.5

      • replace

        public static java.lang.String replace​(java.lang.String text,
                                       java.lang.String searchString,
                                       java.lang.String replacement)

        Replaces all occurrences of a String within another String.

        A null reference passed to this method is a no-op. 

         StringUtils.replace(null, *, *)        = null
 StringUtils.replace("", *, *)          = ""
 StringUtils.replace("any", null, *)    = "any"
 StringUtils.replace("any", *, null)    = "any"
 StringUtils.replace("any", "", *)      = "any"
 StringUtils.replace("aba", "a", null)  = "aba"
 StringUtils.replace("aba", "a", "")    = "b"
 StringUtils.replace("aba", "a", "z")   = "zbz"
        Parameters:
        text - text to search and replace in, may be null
        searchString - the String to search for, may be null
        replacement - the String to replace it with, may be null
        Returns:
        the text with any replacements processed, null if null String input
        See Also:
        replace(String text, String searchString, String replacement, int max)

      • replace

        public static java.lang.String replace​(java.lang.String text,
                                       java.lang.String searchString,
                                       java.lang.String replacement,
                                       int max)

        Replaces a String with another String inside a larger String, for the first max values of the search String.

        A null reference passed to this method is a no-op. 

         StringUtils.replace(null, *, *, *)         = null
 StringUtils.replace("", *, *, *)           = ""
 StringUtils.replace("any", null, *, *)     = "any"
 StringUtils.replace("any", *, null, *)     = "any"
 StringUtils.replace("any", "", *, *)       = "any"
 StringUtils.replace("any", *, *, 0)        = "any"
 StringUtils.replace("abaa", "a", null, -1) = "abaa"
 StringUtils.replace("abaa", "a", "", -1)   = "b"
 StringUtils.replace("abaa", "a", "z", 0)   = "abaa"
 StringUtils.replace("abaa", "a", "z", 1)   = "zbaa"
 StringUtils.replace("abaa", "a", "z", 2)   = "zbza"
 StringUtils.replace("abaa", "a", "z", -1)  = "zbzz"
        Parameters:
        text - text to search and replace in, may be null
        searchString - the String to search for, may be null
        replacement - the String to replace it with, may be null
        max - maximum number of values to replace, or -1 if no maximum
        Returns:
        the text with any replacements processed, null if null String input

      • replaceAll

        @Deprecated
public static java.lang.String replaceAll​(java.lang.String text,
                                          java.lang.String regex,
                                          java.lang.String replacement)
        Deprecated.
        Moved to RegExUtils.

        Replaces each substring of the text String that matches the given regular expression with the given replacement.

        This method is a null safe equivalent to:
        • text.replaceAll(regex, replacement)
        • Pattern.compile(regex).matcher(text).replaceAll(replacement)

        A null reference passed to this method is a no-op.

        Unlike in the replacePattern(String, String, String) method, the Pattern.DOTALL option is NOT automatically added. To use the DOTALL option prepend "(?s)" to the regex. DOTALL is also known as single-line mode in Perl. 

         StringUtils.replaceAll(null, *, *)       = null
 StringUtils.replaceAll("any", (String) null, *)   = "any"
 StringUtils.replaceAll("any", *, null)   = "any"
 StringUtils.replaceAll("", "", "zzz")    = "zzz"
 StringUtils.replaceAll("", ".*", "zzz")  = "zzz"
 StringUtils.replaceAll("", ".+", "zzz")  = ""
 StringUtils.replaceAll("abc", "", "ZZ")  = "ZZaZZbZZcZZ"
 StringUtils.replaceAll("<__>\n<__>", "<.*>", "z")      = "z\nz"
 StringUtils.replaceAll("<__>\n<__>", "(?s)<.*>", "z")  = "z"
 StringUtils.replaceAll("ABCabc123", "[a-z]", "_")       = "ABC___123"
 StringUtils.replaceAll("ABCabc123", "[^A-Z0-9]+", "_")  = "ABC_123"
 StringUtils.replaceAll("ABCabc123", "[^A-Z0-9]+", "")   = "ABC123"
 StringUtils.replaceAll("Lorem ipsum  dolor   sit", "( +)([a-z]+)", "_$2")  = "Lorem_ipsum_dolor_sit"
        Parameters:
        text - text to search and replace in, may be null
        regex - the regular expression to which this string is to be matched
        replacement - the string to be substituted for each match
        Returns:
        the text with any replacements processed, null if null String input
        Throws:
        java.util.regex.PatternSyntaxException - if the regular expression's syntax is invalid
        Since:
        3.5
        See Also:
        replacePattern(String, String, String), String.replaceAll(String, String), Pattern, Pattern.DOTALL

      • replaceChars

        public static java.lang.String replaceChars​(java.lang.String str,
                                            char searchChar,
                                            char replaceChar)

        Replaces all occurrences of a character in a String with another. This is a null-safe version of String.replace(char, char).

        A null string input returns null. An empty ("") string input returns an empty string. 

         StringUtils.replaceChars(null, *, *)        = null
 StringUtils.replaceChars("", *, *)          = ""
 StringUtils.replaceChars("abcba", 'b', 'y') = "aycya"
 StringUtils.replaceChars("abcba", 'z', 'y') = "abcba"
        Parameters:
        str - String to replace characters in, may be null
        searchChar - the character to search for, may be null
        replaceChar - the character to replace, may be null
        Returns:
        modified String, null if null string input
        Since:
        2.0

      • replaceChars

        public static java.lang.String replaceChars​(java.lang.String str,
                                            java.lang.String searchChars,
                                            java.lang.String replaceChars)

        Replaces multiple characters in a String in one go. This method can also be used to delete characters.

        For example:
        replaceChars(&quot;hello&quot;, &quot;ho&quot;, &quot;jy&quot;) = jelly.

        A null string input returns null. An empty ("") string input returns an empty string. A null or empty set of search characters returns the input string.

        The length of the search characters should normally equal the length of the replace characters. If the search characters is longer, then the extra search characters are deleted. If the search characters is shorter, then the extra replace characters are ignored. 

         StringUtils.replaceChars(null, *, *)           = null
 StringUtils.replaceChars("", *, *)             = ""
 StringUtils.replaceChars("abc", null, *)       = "abc"
 StringUtils.replaceChars("abc", "", *)         = "abc"
 StringUtils.replaceChars("abc", "b", null)     = "ac"
 StringUtils.replaceChars("abc", "b", "")       = "ac"
 StringUtils.replaceChars("abcba", "bc", "yz")  = "ayzya"
 StringUtils.replaceChars("abcba", "bc", "y")   = "ayya"
 StringUtils.replaceChars("abcba", "bc", "yzx") = "ayzya"
        Parameters:
        str - String to replace characters in, may be null
        searchChars - a set of characters to search for, may be null
        replaceChars - a set of characters to replace, may be null
        Returns:
        modified String, null if null string input
        Since:
        2.0

      • replaceEach

        public static java.lang.String replaceEach​(java.lang.String text,
                                           java.lang.String[] searchList,
                                           java.lang.String[] replacementList)

        Replaces all occurrences of Strings within another String.

        A null reference passed to this method is a no-op, or if any "search string" or "string to replace" is null, that replace will be ignored. This will not repeat. For repeating replaces, call the overloaded method. 

          StringUtils.replaceEach(null, *, *)        = null
  StringUtils.replaceEach("", *, *)          = ""
  StringUtils.replaceEach("aba", null, null) = "aba"
  StringUtils.replaceEach("aba", new String[0], null) = "aba"
  StringUtils.replaceEach("aba", null, new String[0]) = "aba"
  StringUtils.replaceEach("aba", new String[]{"a"}, null)  = "aba"
  StringUtils.replaceEach("aba", new String[]{"a"}, new String[]{""})  = "b"
  StringUtils.replaceEach("aba", new String[]{null}, new String[]{"a"})  = "aba"
  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"w", "t"})  = "wcte"
  (example of how it does not repeat)
  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"})  = "dcte"
        Parameters:
        text - text to search and replace in, no-op if null
        searchList - the Strings to search for, no-op if null
        replacementList - the Strings to replace them with, no-op if null
        Returns:
        the text with any replacements processed, null if null String input
        Throws:
        java.lang.IllegalArgumentException - if the lengths of the arrays are not the same (null is ok, and/or size 0)
        Since:
        2.4

      • replaceEachRepeatedly

        public static java.lang.String replaceEachRepeatedly​(java.lang.String text,
                                                     java.lang.String[] searchList,
                                                     java.lang.String[] replacementList)

        Replaces all occurrences of Strings within another String.

        A null reference passed to this method is a no-op, or if any "search string" or "string to replace" is null, that replace will be ignored. 

          StringUtils.replaceEachRepeatedly(null, *, *) = null
  StringUtils.replaceEachRepeatedly("", *, *) = ""
  StringUtils.replaceEachRepeatedly("aba", null, null) = "aba"
  StringUtils.replaceEachRepeatedly("aba", new String[0], null) = "aba"
  StringUtils.replaceEachRepeatedly("aba", null, new String[0]) = "aba"
  StringUtils.replaceEachRepeatedly("aba", new String[]{"a"}, null) = "aba"
  StringUtils.replaceEachRepeatedly("aba", new String[]{"a"}, new String[]{""}) = "b"
  StringUtils.replaceEachRepeatedly("aba", new String[]{null}, new String[]{"a"}) = "aba"
  StringUtils.replaceEachRepeatedly("abcde", new String[]{"ab", "d"}, new String[]{"w", "t"}) = "wcte"
  (example of how it repeats)
  StringUtils.replaceEachRepeatedly("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"}) = "tcte"
  StringUtils.replaceEachRepeatedly("abcde", new String[]{"ab", "d"}, new String[]{"d", "ab"}) = IllegalStateException
        Parameters:
        text - text to search and replace in, no-op if null
        searchList - the Strings to search for, no-op if null
        replacementList - the Strings to replace them with, no-op if null
        Returns:
        the text with any replacements processed, null if null String input
        Throws:
        java.lang.IllegalStateException - if the search is repeating and there is an endless loop due to outputs of one being inputs to another
        java.lang.IllegalArgumentException - if the lengths of the arrays are not the same (null is ok, and/or size 0)
        Since:
        2.4

      • replaceFirst

        @Deprecated
public static java.lang.String replaceFirst​(java.lang.String text,
                                            java.lang.String regex,
                                            java.lang.String replacement)
        Deprecated.
        Moved to RegExUtils.

        Replaces the first substring of the text string that matches the given regular expression with the given replacement.

        This method is a null safe equivalent to:
        • text.replaceFirst(regex, replacement)
        • Pattern.compile(regex).matcher(text).replaceFirst(replacement)

        A null reference passed to this method is a no-op.

        The Pattern.DOTALL option is NOT automatically added. To use the DOTALL option prepend "(?s)" to the regex. DOTALL is also known as single-line mode in Perl. 

         StringUtils.replaceFirst(null, *, *)       = null
 StringUtils.replaceFirst("any", (String) null, *)   = "any"
 StringUtils.replaceFirst("any", *, null)   = "any"
 StringUtils.replaceFirst("", "", "zzz")    = "zzz"
 StringUtils.replaceFirst("", ".*", "zzz")  = "zzz"
 StringUtils.replaceFirst("", ".+", "zzz")  = ""
 StringUtils.replaceFirst("abc", "", "ZZ")  = "ZZabc"
 StringUtils.replaceFirst("<__>\n<__>", "<.*>", "z")      = "z\n<__>"
 StringUtils.replaceFirst("<__>\n<__>", "(?s)<.*>", "z")  = "z"
 StringUtils.replaceFirst("ABCabc123", "[a-z]", "_")          = "ABC_bc123"
 StringUtils.replaceFirst("ABCabc123abc", "[^A-Z0-9]+", "_")  = "ABC_123abc"
 StringUtils.replaceFirst("ABCabc123abc", "[^A-Z0-9]+", "")   = "ABC123abc"
 StringUtils.replaceFirst("Lorem ipsum  dolor   sit", "( +)([a-z]+)", "_$2")  = "Lorem_ipsum  dolor   sit"
        Parameters:
        text - text to search and replace in, may be null
        regex - the regular expression to which this string is to be matched
        replacement - the string to be substituted for the first match
        Returns:
        the text with the first replacement processed, null if null String input
        Throws:
        java.util.regex.PatternSyntaxException - if the regular expression's syntax is invalid
        Since:
        3.5
        See Also:
        String.replaceFirst(String, String), Pattern, Pattern.DOTALL

      • replaceIgnoreCase

        public static java.lang.String replaceIgnoreCase​(java.lang.String text,
                                                 java.lang.String searchString,
                                                 java.lang.String replacement)

        Case insensitively replaces all occurrences of a String within another String.

        A null reference passed to this method is a no-op. 

         StringUtils.replaceIgnoreCase(null, *, *)        = null
 StringUtils.replaceIgnoreCase("", *, *)          = ""
 StringUtils.replaceIgnoreCase("any", null, *)    = "any"
 StringUtils.replaceIgnoreCase("any", *, null)    = "any"
 StringUtils.replaceIgnoreCase("any", "", *)      = "any"
 StringUtils.replaceIgnoreCase("aba", "a", null)  = "aba"
 StringUtils.replaceIgnoreCase("abA", "A", "")    = "b"
 StringUtils.replaceIgnoreCase("aba", "A", "z")   = "zbz"
        Parameters:
        text - text to search and replace in, may be null
        searchString - the String to search for (case insensitive), may be null
        replacement - the String to replace it with, may be null
        Returns:
        the text with any replacements processed, null if null String input
        Since:
        3.5
        See Also:
        replaceIgnoreCase(String text, String searchString, String replacement, int max)

      • replaceIgnoreCase

        public static java.lang.String replaceIgnoreCase​(java.lang.String text,
                                                 java.lang.String searchString,
                                                 java.lang.String replacement,
                                                 int max)

        Case insensitively replaces a String with another String inside a larger String, for the first max values of the search String.

        A null reference passed to this method is a no-op. 

         StringUtils.replaceIgnoreCase(null, *, *, *)         = null
 StringUtils.replaceIgnoreCase("", *, *, *)           = ""
 StringUtils.replaceIgnoreCase("any", null, *, *)     = "any"
 StringUtils.replaceIgnoreCase("any", *, null, *)     = "any"
 StringUtils.replaceIgnoreCase("any", "", *, *)       = "any"
 StringUtils.replaceIgnoreCase("any", *, *, 0)        = "any"
 StringUtils.replaceIgnoreCase("abaa", "a", null, -1) = "abaa"
 StringUtils.replaceIgnoreCase("abaa", "a", "", -1)   = "b"
 StringUtils.replaceIgnoreCase("abaa", "a", "z", 0)   = "abaa"
 StringUtils.replaceIgnoreCase("abaa", "A", "z", 1)   = "zbaa"
 StringUtils.replaceIgnoreCase("abAa", "a", "z", 2)   = "zbza"
 StringUtils.replaceIgnoreCase("abAa", "a", "z", -1)  = "zbzz"
        Parameters:
        text - text to search and replace in, may be null
        searchString - the String to search for (case insensitive), may be null
        replacement - the String to replace it with, may be null
        max - maximum number of values to replace, or -1 if no maximum
        Returns:
        the text with any replacements processed, null if null String input
        Since:
        3.5

      • replaceOnce

        public static java.lang.String replaceOnce​(java.lang.String text,
                                           java.lang.String searchString,
                                           java.lang.String replacement)

        Replaces a String with another String inside a larger String, once.

        A null reference passed to this method is a no-op. 

         StringUtils.replaceOnce(null, *, *)        = null
 StringUtils.replaceOnce("", *, *)          = ""
 StringUtils.replaceOnce("any", null, *)    = "any"
 StringUtils.replaceOnce("any", *, null)    = "any"
 StringUtils.replaceOnce("any", "", *)      = "any"
 StringUtils.replaceOnce("aba", "a", null)  = "aba"
 StringUtils.replaceOnce("aba", "a", "")    = "ba"
 StringUtils.replaceOnce("aba", "a", "z")   = "zba"
        Parameters:
        text - text to search and replace in, may be null
        searchString - the String to search for, may be null
        replacement - the String to replace with, may be null
        Returns:
        the text with any replacements processed, null if null String input
        See Also:
        replace(String text, String searchString, String replacement, int max)

      • replaceOnceIgnoreCase

        public static java.lang.String replaceOnceIgnoreCase​(java.lang.String text,
                                                     java.lang.String searchString,
                                                     java.lang.String replacement)

        Case insensitively replaces a String with another String inside a larger String, once.

        A null reference passed to this method is a no-op. 

         StringUtils.replaceOnceIgnoreCase(null, *, *)        = null
 StringUtils.replaceOnceIgnoreCase("", *, *)          = ""
 StringUtils.replaceOnceIgnoreCase("any", null, *)    = "any"
 StringUtils.replaceOnceIgnoreCase("any", *, null)    = "any"
 StringUtils.replaceOnceIgnoreCase("any", "", *)      = "any"
 StringUtils.replaceOnceIgnoreCase("aba", "a", null)  = "aba"
 StringUtils.replaceOnceIgnoreCase("aba", "a", "")    = "ba"
 StringUtils.replaceOnceIgnoreCase("aba", "a", "z")   = "zba"
 StringUtils.replaceOnceIgnoreCase("FoOFoofoo", "foo", "") = "Foofoo"
        Parameters:
        text - text to search and replace in, may be null
        searchString - the String to search for (case insensitive), may be null
        replacement - the String to replace with, may be null
        Returns:
        the text with any replacements processed, null if null String input
        Since:
        3.5
        See Also:
        replaceIgnoreCase(String text, String searchString, String replacement, int max)

      • replacePattern

        @Deprecated
public static java.lang.String replacePattern​(java.lang.String source,
                                              java.lang.String regex,
                                              java.lang.String replacement)
        Deprecated.
        Moved to RegExUtils.

        Replaces each substring of the source String that matches the given regular expression with the given replacement using the Pattern.DOTALL option. DOTALL is also known as single-line mode in Perl.

        This call is a null safe equivalent to:
        • source.replaceAll(&quot;(?s)&quot; + regex, replacement)
        • Pattern.compile(regex, Pattern.DOTALL).matcher(source).replaceAll(replacement)

        A null reference passed to this method is a no-op. 

         StringUtils.replacePattern(null, *, *)       = null
 StringUtils.replacePattern("any", (String) null, *)   = "any"
 StringUtils.replacePattern("any", *, null)   = "any"
 StringUtils.replacePattern("", "", "zzz")    = "zzz"
 StringUtils.replacePattern("", ".*", "zzz")  = "zzz"
 StringUtils.replacePattern("", ".+", "zzz")  = ""
 StringUtils.replacePattern("<__>\n<__>", "<.*>", "z")       = "z"
 StringUtils.replacePattern("ABCabc123", "[a-z]", "_")       = "ABC___123"
 StringUtils.replacePattern("ABCabc123", "[^A-Z0-9]+", "_")  = "ABC_123"
 StringUtils.replacePattern("ABCabc123", "[^A-Z0-9]+", "")   = "ABC123"
 StringUtils.replacePattern("Lorem ipsum  dolor   sit", "( +)([a-z]+)", "_$2")  = "Lorem_ipsum_dolor_sit"
        Parameters:
        source - the source string
        regex - the regular expression to which this string is to be matched
        replacement - the string to be substituted for each match
        Returns:
        The resulting String
        Since:
        3.2, 3.5 Changed null reference passed to this method is a no-op.
        See Also:
        replaceAll(String, String, String), String.replaceAll(String, String), Pattern.DOTALL

      • reverse

        public static java.lang.String reverse​(java.lang.String str)

        Reverses a String as per StringBuilder.reverse().

        A null String returns null. 

         StringUtils.reverse(null)  = null
 StringUtils.reverse("")    = ""
 StringUtils.reverse("bat") = "tab"
        Parameters:
        str - the String to reverse, may be null
        Returns:
        the reversed String, null if null String input

      • reverseDelimited

        public static java.lang.String reverseDelimited​(java.lang.String str,
                                                char separatorChar)

        Reverses a String that is delimited by a specific character.

        The Strings between the delimiters are not reversed. Thus java.lang.String becomes String.lang.java (if the delimiter is '.'). 

         StringUtils.reverseDelimited(null, *)      = null
 StringUtils.reverseDelimited("", *)        = ""
 StringUtils.reverseDelimited("a.b.c", 'x') = "a.b.c"
 StringUtils.reverseDelimited("a.b.c", ".") = "c.b.a"
        Parameters:
        str - the String to reverse, may be null
        separatorChar - the separator character to use
        Returns:
        the reversed String, null if null String input
        Since:
        2.0

      • right

        public static java.lang.String right​(java.lang.String str,
                                     int len)

        Gets the rightmost len characters of a String.

        If len characters are not available, or the String is null, the String will be returned without an an exception. An empty String is returned if len is negative. 

         StringUtils.right(null, *)    = null
 StringUtils.right(*, -ve)     = ""
 StringUtils.right("", *)      = ""
 StringUtils.right("abc", 0)   = ""
 StringUtils.right("abc", 2)   = "bc"
 StringUtils.right("abc", 4)   = "abc"
        Parameters:
        str - the String to get the rightmost characters from, may be null
        len - the length of the required String
        Returns:
        the rightmost characters, null if null String input

      • rightPad

        public static java.lang.String rightPad​(java.lang.String str,
                                        int size)

        Right pad a String with spaces (' ').

        The String is padded to the size of size. 

         StringUtils.rightPad(null, *)   = null
 StringUtils.rightPad("", 3)     = "   "
 StringUtils.rightPad("bat", 3)  = "bat"
 StringUtils.rightPad("bat", 5)  = "bat  "
 StringUtils.rightPad("bat", 1)  = "bat"
 StringUtils.rightPad("bat", -1) = "bat"
        Parameters:
        str - the String to pad out, may be null
        size - the size to pad to
        Returns:
        right padded String or original String if no padding is necessary, null if null String input

      • rightPad

        public static java.lang.String rightPad​(java.lang.String str,
                                        int size,
                                        char padChar)

        Right pad a String with a specified character.

        The String is padded to the size of size. 

         StringUtils.rightPad(null, *, *)     = null
 StringUtils.rightPad("", 3, 'z')     = "zzz"
 StringUtils.rightPad("bat", 3, 'z')  = "bat"
 StringUtils.rightPad("bat", 5, 'z')  = "batzz"
 StringUtils.rightPad("bat", 1, 'z')  = "bat"
 StringUtils.rightPad("bat", -1, 'z') = "bat"
        Parameters:
        str - the String to pad out, may be null
        size - the size to pad to
        padChar - the character to pad with
        Returns:
        right padded String or original String if no padding is necessary, null if null String input
        Since:
        2.0

      • rightPad

        public static java.lang.String rightPad​(java.lang.String str,
                                        int size,
                                        java.lang.String padStr)

        Right pad a String with a specified String.

        The String is padded to the size of size. 

         StringUtils.rightPad(null, *, *)      = null
 StringUtils.rightPad("", 3, "z")      = "zzz"
 StringUtils.rightPad("bat", 3, "yz")  = "bat"
 StringUtils.rightPad("bat", 5, "yz")  = "batyz"
 StringUtils.rightPad("bat", 8, "yz")  = "batyzyzy"
 StringUtils.rightPad("bat", 1, "yz")  = "bat"
 StringUtils.rightPad("bat", -1, "yz") = "bat"
 StringUtils.rightPad("bat", 5, null)  = "bat  "
 StringUtils.rightPad("bat", 5, "")    = "bat  "
        Parameters:
        str - the String to pad out, may be null
        size - the size to pad to
        padStr - the String to pad with, null or empty treated as single space
        Returns:
        right padded String or original String if no padding is necessary, null if null String input

      • rotate

        public static java.lang.String rotate​(java.lang.String str,
                                      int shift)

        Rotate (circular shift) a String of shift characters.

        • If shift > 0, right circular shift (ex : ABCDEF => FABCDE)
        • If shift < 0, left circular shift (ex : ABCDEF => BCDEFA)
         StringUtils.rotate(null, *)        = null
 StringUtils.rotate("", *)          = ""
 StringUtils.rotate("abcdefg", 0)   = "abcdefg"
 StringUtils.rotate("abcdefg", 2)   = "fgabcde"
 StringUtils.rotate("abcdefg", -2)  = "cdefgab"
 StringUtils.rotate("abcdefg", 7)   = "abcdefg"
 StringUtils.rotate("abcdefg", -7)  = "abcdefg"
 StringUtils.rotate("abcdefg", 9)   = "fgabcde"
 StringUtils.rotate("abcdefg", -9)  = "cdefgab"
        Parameters:
        str - the String to rotate, may be null
        shift - number of time to shift (positive : right shift, negative : left shift)
        Returns:
        the rotated String, or the original String if shift == 0, or null if null String input
        Since:
        3.5

      • split

        public static java.lang.String[] split​(java.lang.String str)

        Splits the provided text into an array, using whitespace as the separator. Whitespace is defined by Character.isWhitespace(char).

        The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.

        A null input String returns null. 

         StringUtils.split(null)       = null
 StringUtils.split("")         = []
 StringUtils.split("abc def")  = ["abc", "def"]
 StringUtils.split("abc  def") = ["abc", "def"]
 StringUtils.split(" abc ")    = ["abc"]
        Parameters:
        str - the String to parse, may be null
        Returns:
        an array of parsed Strings, null if null String input

      • split

        public static java.lang.String[] split​(java.lang.String str,
                                       char separatorChar)

        Splits the provided text into an array, separator specified. This is an alternative to using StringTokenizer.

        The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.

        A null input String returns null. 

         StringUtils.split(null, *)         = null
 StringUtils.split("", *)           = []
 StringUtils.split("a.b.c", '.')    = ["a", "b", "c"]
 StringUtils.split("a..b.c", '.')   = ["a", "b", "c"]
 StringUtils.split("a:b:c", '.')    = ["a:b:c"]
 StringUtils.split("a b c", ' ')    = ["a", "b", "c"]
        Parameters:
        str - the String to parse, may be null
        separatorChar - the character used as the delimiter
        Returns:
        an array of parsed Strings, null if null String input
        Since:
        2.0

      • split

        public static java.lang.String[] split​(java.lang.String str,
                                       java.lang.String separatorChars)

        Splits the provided text into an array, separators specified. This is an alternative to using StringTokenizer.

        The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.

        A null input String returns null. A null separatorChars splits on whitespace. 

         StringUtils.split(null, *)         = null
 StringUtils.split("", *)           = []
 StringUtils.split("abc def", null) = ["abc", "def"]
 StringUtils.split("abc def", " ")  = ["abc", "def"]
 StringUtils.split("abc  def", " ") = ["abc", "def"]
 StringUtils.split("ab:cd:ef", ":") = ["ab", "cd", "ef"]
        Parameters:
        str - the String to parse, may be null
        separatorChars - the characters used as the delimiters, null splits on whitespace
        Returns:
        an array of parsed Strings, null if null String input

      • split

        public static java.lang.String[] split​(java.lang.String str,
                                       java.lang.String separatorChars,
                                       int max)

        Splits the provided text into an array with a maximum length, separators specified.

        The separator is not included in the returned String array. Adjacent separators are treated as one separator.

        A null input String returns null. A null separatorChars splits on whitespace.

        If more than max delimited substrings are found, the last returned string includes all characters after the first max - 1 returned strings (including separator characters). 

         StringUtils.split(null, *, *)            = null
 StringUtils.split("", *, *)              = []
 StringUtils.split("ab cd ef", null, 0)   = ["ab", "cd", "ef"]
 StringUtils.split("ab   cd ef", null, 0) = ["ab", "cd", "ef"]
 StringUtils.split("ab:cd:ef", ":", 0)    = ["ab", "cd", "ef"]
 StringUtils.split("ab:cd:ef", ":", 2)    = ["ab", "cd:ef"]
        Parameters:
        str - the String to parse, may be null
        separatorChars - the characters used as the delimiters, null splits on whitespace
        max - the maximum number of elements to include in the array. A zero or negative value implies no limit
        Returns:
        an array of parsed Strings, null if null String input

      • splitByCharacterType

        public static java.lang.String[] splitByCharacterType​(java.lang.String str)

        Splits a String by Character type as returned by java.lang.Character.getType(char). Groups of contiguous characters of the same type are returned as complete tokens. 

         StringUtils.splitByCharacterType(null)         = null
 StringUtils.splitByCharacterType("")           = []
 StringUtils.splitByCharacterType("ab de fg")   = ["ab", " ", "de", " ", "fg"]
 StringUtils.splitByCharacterType("ab   de fg") = ["ab", "   ", "de", " ", "fg"]
 StringUtils.splitByCharacterType("ab:cd:ef")   = ["ab", ":", "cd", ":", "ef"]
 StringUtils.splitByCharacterType("number5")    = ["number", "5"]
 StringUtils.splitByCharacterType("fooBar")     = ["foo", "B", "ar"]
 StringUtils.splitByCharacterType("foo200Bar")  = ["foo", "200", "B", "ar"]
 StringUtils.splitByCharacterType("ASFRules")   = ["ASFR", "ules"]
        Parameters:
        str - the String to split, may be null
        Returns:
        an array of parsed Strings, null if null String input
        Since:
        2.4

      • splitByCharacterTypeCamelCase

        public static java.lang.String[] splitByCharacterTypeCamelCase​(java.lang.String str)

        Splits a String by Character type as returned by java.lang.Character.getType(char). Groups of contiguous characters of the same type are returned as complete tokens, with the following exception: the character of type Character.UPPERCASE_LETTER, if any, immediately preceding a token of type Character.LOWERCASE_LETTER will belong to the following token rather than to the preceding, if any, Character.UPPERCASE_LETTER token. 

         StringUtils.splitByCharacterTypeCamelCase(null)         = null
 StringUtils.splitByCharacterTypeCamelCase("")           = []
 StringUtils.splitByCharacterTypeCamelCase("ab de fg")   = ["ab", " ", "de", " ", "fg"]
 StringUtils.splitByCharacterTypeCamelCase("ab   de fg") = ["ab", "   ", "de", " ", "fg"]
 StringUtils.splitByCharacterTypeCamelCase("ab:cd:ef")   = ["ab", ":", "cd", ":", "ef"]
 StringUtils.splitByCharacterTypeCamelCase("number5")    = ["number", "5"]
 StringUtils.splitByCharacterTypeCamelCase("fooBar")     = ["foo", "Bar"]
 StringUtils.splitByCharacterTypeCamelCase("foo200Bar")  = ["foo", "200", "Bar"]
 StringUtils.splitByCharacterTypeCamelCase("ASFRules")   = ["ASF", "Rules"]
        Parameters:
        str - the String to split, may be null
        Returns:
        an array of parsed Strings, null if null String input
        Since:
        2.4

      • splitByWholeSeparator

        public static java.lang.String[] splitByWholeSeparator​(java.lang.String str,
                                                       java.lang.String separator)

        Splits the provided text into an array, separator string specified.

        The separator(s) will not be included in the returned String array. Adjacent separators are treated as one separator.

        A null input String returns null. A null separator splits on whitespace. 

         StringUtils.splitByWholeSeparator(null, *)               = null
 StringUtils.splitByWholeSeparator("", *)                 = []
 StringUtils.splitByWholeSeparator("ab de fg", null)      = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparator("ab   de fg", null)    = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparator("ab:cd:ef", ":")       = ["ab", "cd", "ef"]
 StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
        Parameters:
        str - the String to parse, may be null
        separator - String containing the String to be used as a delimiter, null splits on whitespace
        Returns:
        an array of parsed Strings, null if null String was input

      • splitByWholeSeparator

        public static java.lang.String[] splitByWholeSeparator​(java.lang.String str,
                                                       java.lang.String separator,
                                                       int max)

        Splits the provided text into an array, separator string specified. Returns a maximum of max substrings.

        The separator(s) will not be included in the returned String array. Adjacent separators are treated as one separator.

        A null input String returns null. A null separator splits on whitespace. 

         StringUtils.splitByWholeSeparator(null, *, *)               = null
 StringUtils.splitByWholeSeparator("", *, *)                 = []
 StringUtils.splitByWholeSeparator("ab de fg", null, 0)      = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparator("ab   de fg", null, 0)    = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparator("ab:cd:ef", ":", 2)       = ["ab", "cd:ef"]
 StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"]
 StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
        Parameters:
        str - the String to parse, may be null
        separator - String containing the String to be used as a delimiter, null splits on whitespace
        max - the maximum number of elements to include in the returned array. A zero or negative value implies no limit.
        Returns:
        an array of parsed Strings, null if null String was input

      • splitByWholeSeparatorPreserveAllTokens

        public static java.lang.String[] splitByWholeSeparatorPreserveAllTokens​(java.lang.String str,
                                                                        java.lang.String separator)

        Splits the provided text into an array, separator string specified.

        The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.

        A null input String returns null. A null separator splits on whitespace. 

         StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *)               = null
 StringUtils.splitByWholeSeparatorPreserveAllTokens("", *)                 = []
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null)      = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab   de fg", null)    = ["ab", "", "", "de", "fg"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":")       = ["ab", "cd", "ef"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
        Parameters:
        str - the String to parse, may be null
        separator - String containing the String to be used as a delimiter, null splits on whitespace
        Returns:
        an array of parsed Strings, null if null String was input
        Since:
        2.4

      • splitByWholeSeparatorPreserveAllTokens

        public static java.lang.String[] splitByWholeSeparatorPreserveAllTokens​(java.lang.String str,
                                                                        java.lang.String separator,
                                                                        int max)

        Splits the provided text into an array, separator string specified. Returns a maximum of max substrings.

        The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.

        A null input String returns null. A null separator splits on whitespace. 

         StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *, *)               = null
 StringUtils.splitByWholeSeparatorPreserveAllTokens("", *, *)                 = []
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null, 0)      = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab   de fg", null, 0)    = ["ab", "", "", "de", "fg"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":", 2)       = ["ab", "cd:ef"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
        Parameters:
        str - the String to parse, may be null
        separator - String containing the String to be used as a delimiter, null splits on whitespace
        max - the maximum number of elements to include in the returned array. A zero or negative value implies no limit.
        Returns:
        an array of parsed Strings, null if null String was input
        Since:
        2.4

      • splitPreserveAllTokens

        public static java.lang.String[] splitPreserveAllTokens​(java.lang.String str)

        Splits the provided text into an array, using whitespace as the separator, preserving all tokens, including empty tokens created by adjacent separators. This is an alternative to using StringTokenizer. Whitespace is defined by Character.isWhitespace(char).

        The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.

        A null input String returns null. 

         StringUtils.splitPreserveAllTokens(null)       = null
 StringUtils.splitPreserveAllTokens("")         = []
 StringUtils.splitPreserveAllTokens("abc def")  = ["abc", "def"]
 StringUtils.splitPreserveAllTokens("abc  def") = ["abc", "", "def"]
 StringUtils.splitPreserveAllTokens(" abc ")    = ["", "abc", ""]
        Parameters:
        str - the String to parse, may be null
        Returns:
        an array of parsed Strings, null if null String input
        Since:
        2.1

      • splitPreserveAllTokens

        public static java.lang.String[] splitPreserveAllTokens​(java.lang.String str,
                                                        char separatorChar)

        Splits the provided text into an array, separator specified, preserving all tokens, including empty tokens created by adjacent separators. This is an alternative to using StringTokenizer.

        The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.

        A null input String returns null. 

         StringUtils.splitPreserveAllTokens(null, *)         = null
 StringUtils.splitPreserveAllTokens("", *)           = []
 StringUtils.splitPreserveAllTokens("a.b.c", '.')    = ["a", "b", "c"]
 StringUtils.splitPreserveAllTokens("a..b.c", '.')   = ["a", "", "b", "c"]
 StringUtils.splitPreserveAllTokens("a:b:c", '.')    = ["a:b:c"]
 StringUtils.splitPreserveAllTokens("a\tb\nc", null) = ["a", "b", "c"]
 StringUtils.splitPreserveAllTokens("a b c", ' ')    = ["a", "b", "c"]
 StringUtils.splitPreserveAllTokens("a b c ", ' ')   = ["a", "b", "c", ""]
 StringUtils.splitPreserveAllTokens("a b c  ", ' ')   = ["a", "b", "c", "", ""]
 StringUtils.splitPreserveAllTokens(" a b c", ' ')   = ["", a", "b", "c"]
 StringUtils.splitPreserveAllTokens("  a b c", ' ')  = ["", "", a", "b", "c"]
 StringUtils.splitPreserveAllTokens(" a b c ", ' ')  = ["", a", "b", "c", ""]
        Parameters:
        str - the String to parse, may be null
        separatorChar - the character used as the delimiter, null splits on whitespace
        Returns:
        an array of parsed Strings, null if null String input
        Since:
        2.1

      • splitPreserveAllTokens

        public static java.lang.String[] splitPreserveAllTokens​(java.lang.String str,
                                                        java.lang.String separatorChars)

        Splits the provided text into an array, separators specified, preserving all tokens, including empty tokens created by adjacent separators. This is an alternative to using StringTokenizer.

        The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.

        A null input String returns null. A null separatorChars splits on whitespace. 

         StringUtils.splitPreserveAllTokens(null, *)           = null
 StringUtils.splitPreserveAllTokens("", *)             = []
 StringUtils.splitPreserveAllTokens("abc def", null)   = ["abc", "def"]
 StringUtils.splitPreserveAllTokens("abc def", " ")    = ["abc", "def"]
 StringUtils.splitPreserveAllTokens("abc  def", " ")   = ["abc", "", def"]
 StringUtils.splitPreserveAllTokens("ab:cd:ef", ":")   = ["ab", "cd", "ef"]
 StringUtils.splitPreserveAllTokens("ab:cd:ef:", ":")  = ["ab", "cd", "ef", ""]
 StringUtils.splitPreserveAllTokens("ab:cd:ef::", ":") = ["ab", "cd", "ef", "", ""]
 StringUtils.splitPreserveAllTokens("ab::cd:ef", ":")  = ["ab", "", cd", "ef"]
 StringUtils.splitPreserveAllTokens(":cd:ef", ":")     = ["", cd", "ef"]
 StringUtils.splitPreserveAllTokens("::cd:ef", ":")    = ["", "", cd", "ef"]
 StringUtils.splitPreserveAllTokens(":cd:ef:", ":")    = ["", cd", "ef", ""]
        Parameters:
        str - the String to parse, may be null
        separatorChars - the characters used as the delimiters, null splits on whitespace
        Returns:
        an array of parsed Strings, null if null String input
        Since:
        2.1

      • splitPreserveAllTokens

        public static java.lang.String[] splitPreserveAllTokens​(java.lang.String str,
                                                        java.lang.String separatorChars,
                                                        int max)

        Splits the provided text into an array with a maximum length, separators specified, preserving all tokens, including empty tokens created by adjacent separators.

        The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. Adjacent separators are treated as one separator.

        A null input String returns null. A null separatorChars splits on whitespace.

        If more than max delimited substrings are found, the last returned string includes all characters after the first max - 1 returned strings (including separator characters). 

         StringUtils.splitPreserveAllTokens(null, *, *)            = null
 StringUtils.splitPreserveAllTokens("", *, *)              = []
 StringUtils.splitPreserveAllTokens("ab de fg", null, 0)   = ["ab", "de", "fg"]
 StringUtils.splitPreserveAllTokens("ab   de fg", null, 0) = ["ab", "", "", "de", "fg"]
 StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 0)    = ["ab", "cd", "ef"]
 StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 2)    = ["ab", "cd:ef"]
 StringUtils.splitPreserveAllTokens("ab   de fg", null, 2) = ["ab", "  de fg"]
 StringUtils.splitPreserveAllTokens("ab   de fg", null, 3) = ["ab", "", " de fg"]
 StringUtils.splitPreserveAllTokens("ab   de fg", null, 4) = ["ab", "", "", "de fg"]
        Parameters:
        str - the String to parse, may be null
        separatorChars - the characters used as the delimiters, null splits on whitespace
        max - the maximum number of elements to include in the array. A zero or negative value implies no limit
        Returns:
        an array of parsed Strings, null if null String input
        Since:
        2.1

      • startsWith

        public static boolean startsWith​(java.lang.CharSequence str,
                                 java.lang.CharSequence prefix)

        Check if a CharSequence starts with a specified prefix.

        nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case sensitive. 

         StringUtils.startsWith(null, null)      = true
 StringUtils.startsWith(null, "abc")     = false
 StringUtils.startsWith("abcdef", null)  = false
 StringUtils.startsWith("abcdef", "abc") = true
 StringUtils.startsWith("ABCDEF", "abc") = false
        Parameters:
        str - the CharSequence to check, may be null
        prefix - the prefix to find, may be null
        Returns:
        true if the CharSequence starts with the prefix, case sensitive, or both null
        Since:
        2.4, 3.0 Changed signature from startsWith(String, String) to startsWith(CharSequence, CharSequence)
        See Also:
        String.startsWith(String)

      • startsWithAny

        public static boolean startsWithAny​(java.lang.CharSequence sequence,
                                    java.lang.CharSequence... searchStrings)

        Check if a CharSequence starts with any of the provided case-sensitive prefixes. 

         StringUtils.startsWithAny(null, null)      = false
 StringUtils.startsWithAny(null, new String[] {"abc"})  = false
 StringUtils.startsWithAny("abcxyz", null)     = false
 StringUtils.startsWithAny("abcxyz", new String[] {""}) = true
 StringUtils.startsWithAny("abcxyz", new String[] {"abc"}) = true
 StringUtils.startsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
 StringUtils.startsWithAny("abcxyz", null, "xyz", "ABCX") = false
 StringUtils.startsWithAny("ABCXYZ", null, "xyz", "abc") = false
        Parameters:
        sequence - the CharSequence to check, may be null
        searchStrings - the case-sensitive CharSequence prefixes, may be empty or contain null
        Returns:
        true if the input sequence is null AND no searchStrings are provided, or the input sequence begins with any of the provided case-sensitive searchStrings.
        Since:
        2.5, 3.0 Changed signature from startsWithAny(String, String[]) to startsWithAny(CharSequence, CharSequence...)
        See Also:
        startsWith(CharSequence, CharSequence)

      • startsWithIgnoreCase

        public static boolean startsWithIgnoreCase​(java.lang.CharSequence str,
                                           java.lang.CharSequence prefix)

        Case insensitive check if a CharSequence starts with a specified prefix.

        nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case insensitive. 

         StringUtils.startsWithIgnoreCase(null, null)      = true
 StringUtils.startsWithIgnoreCase(null, "abc")     = false
 StringUtils.startsWithIgnoreCase("abcdef", null)  = false
 StringUtils.startsWithIgnoreCase("abcdef", "abc") = true
 StringUtils.startsWithIgnoreCase("ABCDEF", "abc") = true
        Parameters:
        str - the CharSequence to check, may be null
        prefix - the prefix to find, may be null
        Returns:
        true if the CharSequence starts with the prefix, case insensitive, or both null
        Since:
        2.4, 3.0 Changed signature from startsWithIgnoreCase(String, String) to startsWithIgnoreCase(CharSequence, CharSequence)
        See Also:
        String.startsWith(String)

      • strip

        public static java.lang.String strip​(java.lang.String str)

        Strips whitespace from the start and end of a String.

        This is similar to trim(String) but removes whitespace. Whitespace is defined by Character.isWhitespace(char).

        A null input String returns null. 

         StringUtils.strip(null)     = null
 StringUtils.strip("")       = ""
 StringUtils.strip("   ")    = ""
 StringUtils.strip("abc")    = "abc"
 StringUtils.strip("  abc")  = "abc"
 StringUtils.strip("abc  ")  = "abc"
 StringUtils.strip(" abc ")  = "abc"
 StringUtils.strip(" ab c ") = "ab c"
        Parameters:
        str - the String to remove whitespace from, may be null
        Returns:
        the stripped String, null if null String input

      • strip

        public static java.lang.String strip​(java.lang.String str,
                                     java.lang.String stripChars)

        Strips any of a set of characters from the start and end of a String. This is similar to String.trim() but allows the characters to be stripped to be controlled.

        A null input String returns null. An empty string ("") input returns the empty string.

        If the stripChars String is null, whitespace is stripped as defined by Character.isWhitespace(char). Alternatively use strip(String). 

         StringUtils.strip(null, *)          = null
 StringUtils.strip("", *)            = ""
 StringUtils.strip("abc", null)      = "abc"
 StringUtils.strip("  abc", null)    = "abc"
 StringUtils.strip("abc  ", null)    = "abc"
 StringUtils.strip(" abc ", null)    = "abc"
 StringUtils.strip("  abcyx", "xyz") = "  abc"
        Parameters:
        str - the String to remove characters from, may be null
        stripChars - the characters to remove, null treated as whitespace
        Returns:
        the stripped String, null if null String input

      • stripAccents

        public static java.lang.String stripAccents​(java.lang.String input)

        Removes diacritics (~= accents) from a string. The case will not be altered.

        For instance, 'à' will be replaced by 'a'.

        Note that ligatures will be left as is. 

         StringUtils.stripAccents(null)                = null
 StringUtils.stripAccents("")                  = ""
 StringUtils.stripAccents("control")           = "control"
 StringUtils.stripAccents("éclair")     = "eclair"
        Parameters:
        input - String to be stripped
        Returns:
        input text with diacritics removed
        Since:
        3.0

      • stripAll

        public static java.lang.String[] stripAll​(java.lang.String... strs)

        Strips whitespace from the start and end of every String in an array. Whitespace is defined by Character.isWhitespace(char).

        A new array is returned each time, except for length zero. A null array will return null. An empty array will return itself. A null array entry will be ignored. 

         StringUtils.stripAll(null)             = null
 StringUtils.stripAll([])               = []
 StringUtils.stripAll(["abc", "  abc"]) = ["abc", "abc"]
 StringUtils.stripAll(["abc  ", null])  = ["abc", null]
        Parameters:
        strs - the array to remove whitespace from, may be null
        Returns:
        the stripped Strings, null if null array input

      • stripAll

        public static java.lang.String[] stripAll​(java.lang.String[] strs,
                                          java.lang.String stripChars)

        Strips any of a set of characters from the start and end of every String in an array.

        Whitespace is defined by Character.isWhitespace(char).

        A new array is returned each time, except for length zero. A null array will return null. An empty array will return itself. A null array entry will be ignored. A null stripChars will strip whitespace as defined by Character.isWhitespace(char). 

         StringUtils.stripAll(null, *)                = null
 StringUtils.stripAll([], *)                  = []
 StringUtils.stripAll(["abc", "  abc"], null) = ["abc", "abc"]
 StringUtils.stripAll(["abc  ", null], null)  = ["abc", null]
 StringUtils.stripAll(["abc  ", null], "yz")  = ["abc  ", null]
 StringUtils.stripAll(["yabcz", null], "yz")  = ["abc", null]
        Parameters:
        strs - the array to remove characters from, may be null
        stripChars - the characters to remove, null treated as whitespace
        Returns:
        the stripped Strings, null if null array input

      • stripEnd

        public static java.lang.String stripEnd​(java.lang.String str,
                                        java.lang.String stripChars)

        Strips any of a set of characters from the end of a String.

        A null input String returns null. An empty string ("") input returns the empty string.

        If the stripChars String is null, whitespace is stripped as defined by Character.isWhitespace(char). 

         StringUtils.stripEnd(null, *)          = null
 StringUtils.stripEnd("", *)            = ""
 StringUtils.stripEnd("abc", "")        = "abc"
 StringUtils.stripEnd("abc", null)      = "abc"
 StringUtils.stripEnd("  abc", null)    = "  abc"
 StringUtils.stripEnd("abc  ", null)    = "abc"
 StringUtils.stripEnd(" abc ", null)    = " abc"
 StringUtils.stripEnd("  abcyx", "xyz") = "  abc"
 StringUtils.stripEnd("120.00", ".0")   = "12"
        Parameters:
        str - the String to remove characters from, may be null
        stripChars - the set of characters to remove, null treated as whitespace
        Returns:
        the stripped String, null if null String input

      • stripStart

        public static java.lang.String stripStart​(java.lang.String str,
                                          java.lang.String stripChars)

        Strips any of a set of characters from the start of a String.

        A null input String returns null. An empty string ("") input returns the empty string.

        If the stripChars String is null, whitespace is stripped as defined by Character.isWhitespace(char). 

         StringUtils.stripStart(null, *)          = null
 StringUtils.stripStart("", *)            = ""
 StringUtils.stripStart("abc", "")        = "abc"
 StringUtils.stripStart("abc", null)      = "abc"
 StringUtils.stripStart("  abc", null)    = "abc"
 StringUtils.stripStart("abc  ", null)    = "abc  "
 StringUtils.stripStart(" abc ", null)    = "abc "
 StringUtils.stripStart("yxabc  ", "xyz") = "abc  "
        Parameters:
        str - the String to remove characters from, may be null
        stripChars - the characters to remove, null treated as whitespace
        Returns:
        the stripped String, null if null String input

      • stripToEmpty

        public static java.lang.String stripToEmpty​(java.lang.String str)

        Strips whitespace from the start and end of a String returning an empty String if null input.

        This is similar to trimToEmpty(String) but removes whitespace. Whitespace is defined by Character.isWhitespace(char). 

         StringUtils.stripToEmpty(null)     = ""
 StringUtils.stripToEmpty("")       = ""
 StringUtils.stripToEmpty("   ")    = ""
 StringUtils.stripToEmpty("abc")    = "abc"
 StringUtils.stripToEmpty("  abc")  = "abc"
 StringUtils.stripToEmpty("abc  ")  = "abc"
 StringUtils.stripToEmpty(" abc ")  = "abc"
 StringUtils.stripToEmpty(" ab c ") = "ab c"
        Parameters:
        str - the String to be stripped, may be null
        Returns:
        the trimmed String, or an empty String if null input
        Since:
        2.0

      • stripToNull

        public static java.lang.String stripToNull​(java.lang.String str)

        Strips whitespace from the start and end of a String returning null if the String is empty ("") after the strip.

        This is similar to trimToNull(String) but removes whitespace. Whitespace is defined by Character.isWhitespace(char). 

         StringUtils.stripToNull(null)     = null
 StringUtils.stripToNull("")       = null
 StringUtils.stripToNull("   ")    = null
 StringUtils.stripToNull("abc")    = "abc"
 StringUtils.stripToNull("  abc")  = "abc"
 StringUtils.stripToNull("abc  ")  = "abc"
 StringUtils.stripToNull(" abc ")  = "abc"
 StringUtils.stripToNull(" ab c ") = "ab c"
        Parameters:
        str - the String to be stripped, may be null
        Returns:
        the stripped String, null if whitespace, empty or null String input
        Since:
        2.0

      • substring

        public static java.lang.String substring​(java.lang.String str,
                                         int start)

        Gets a substring from the specified String avoiding exceptions.

        A negative start position can be used to start n characters from the end of the String.

        A null String will return null. An empty ("") String will return "". 

         StringUtils.substring(null, *)   = null
 StringUtils.substring("", *)     = ""
 StringUtils.substring("abc", 0)  = "abc"
 StringUtils.substring("abc", 2)  = "c"
 StringUtils.substring("abc", 4)  = ""
 StringUtils.substring("abc", -2) = "bc"
 StringUtils.substring("abc", -4) = "abc"
        Parameters:
        str - the String to get the substring from, may be null
        start - the position to start from, negative means count back from the end of the String by this many characters
        Returns:
        substring from start position, null if null String input

      • substring

        public static java.lang.String substring​(java.lang.String str,
                                         int start,
                                         int end)

        Gets a substring from the specified String avoiding exceptions.

        A negative start position can be used to start/end n characters from the end of the String.

        The returned substring starts with the character in the start position and ends before the end position. All position counting is zero-based -- i.e., to start at the beginning of the string use start = 0. Negative start and end positions can be used to specify offsets relative to the end of the String.

        If start is not strictly to the left of end, "" is returned. 

         StringUtils.substring(null, *, *)    = null
 StringUtils.substring("", * ,  *)    = "";
 StringUtils.substring("abc", 0, 2)   = "ab"
 StringUtils.substring("abc", 2, 0)   = ""
 StringUtils.substring("abc", 2, 4)   = "c"
 StringUtils.substring("abc", 4, 6)   = ""
 StringUtils.substring("abc", 2, 2)   = ""
 StringUtils.substring("abc", -2, -1) = "b"
 StringUtils.substring("abc", -4, 2)  = "ab"
        Parameters:
        str - the String to get the substring from, may be null
        start - the position to start from, negative means count back from the end of the String by this many characters
        end - the position to end at (exclusive), negative means count back from the end of the String by this many characters
        Returns:
        substring from start position to end position, null if null String input

      • substringAfter

        public static java.lang.String substringAfter​(java.lang.String str,
                                              int separator)

        Gets the substring after the first occurrence of a separator. The separator is not returned.

        A null string input will return null. An empty ("") string input will return the empty string.

        If nothing is found, the empty string is returned. 

         StringUtils.substringAfter(null, *)      = null
 StringUtils.substringAfter("", *)        = ""
 StringUtils.substringAfter("abc", 'a')   = "bc"
 StringUtils.substringAfter("abcba", 'b') = "cba"
 StringUtils.substringAfter("abc", 'c')   = ""
 StringUtils.substringAfter("abc", 'd')   = ""
 StringUtils.substringAfter(" abc", 32)   = "abc"
        Parameters:
        str - the String to get a substring from, may be null
        separator - the character to search.
        Returns:
        the substring after the first occurrence of the separator, null if null String input
        Since:
        3.11

      • substringAfter

        public static java.lang.String substringAfter​(java.lang.String str,
                                              java.lang.String separator)

        Gets the substring after the first occurrence of a separator. The separator is not returned.

        A null string input will return null. An empty ("") string input will return the empty string. A null separator will return the empty string if the input string is not null.

        If nothing is found, the empty string is returned. 

         StringUtils.substringAfter(null, *)      = null
 StringUtils.substringAfter("", *)        = ""
 StringUtils.substringAfter(*, null)      = ""
 StringUtils.substringAfter("abc", "a")   = "bc"
 StringUtils.substringAfter("abcba", "b") = "cba"
 StringUtils.substringAfter("abc", "c")   = ""
 StringUtils.substringAfter("abc", "d")   = ""
 StringUtils.substringAfter("abc", "")    = "abc"
        Parameters:
        str - the String to get a substring from, may be null
        separator - the String to search for, may be null
        Returns:
        the substring after the first occurrence of the separator, null if null String input
        Since:
        2.0

      • substringAfterLast

        public static java.lang.String substringAfterLast​(java.lang.String str,
                                                  int separator)

        Gets the substring after the last occurrence of a separator. The separator is not returned.

        A null string input will return null. An empty ("") string input will return the empty string.

        If nothing is found, the empty string is returned. 

         StringUtils.substringAfterLast(null, *)      = null
 StringUtils.substringAfterLast("", *)        = ""
 StringUtils.substringAfterLast("abc", 'a')   = "bc"
 StringUtils.substringAfterLast(" bc", 32)    = "bc"
 StringUtils.substringAfterLast("abcba", 'b') = "a"
 StringUtils.substringAfterLast("abc", 'c')   = ""
 StringUtils.substringAfterLast("a", 'a')     = ""
 StringUtils.substringAfterLast("a", 'z')     = ""
        Parameters:
        str - the String to get a substring from, may be null
        separator - the String to search for, may be null
        Returns:
        the substring after the last occurrence of the separator, null if null String input
        Since:
        3.11

      • substringAfterLast

        public static java.lang.String substringAfterLast​(java.lang.String str,
                                                  java.lang.String separator)

        Gets the substring after the last occurrence of a separator. The separator is not returned.

        A null string input will return null. An empty ("") string input will return the empty string. An empty or null separator will return the empty string if the input string is not null.

        If nothing is found, the empty string is returned. 

         StringUtils.substringAfterLast(null, *)      = null
 StringUtils.substringAfterLast("", *)        = ""
 StringUtils.substringAfterLast(*, "")        = ""
 StringUtils.substringAfterLast(*, null)      = ""
 StringUtils.substringAfterLast("abc", "a")   = "bc"
 StringUtils.substringAfterLast("abcba", "b") = "a"
 StringUtils.substringAfterLast("abc", "c")   = ""
 StringUtils.substringAfterLast("a", "a")     = ""
 StringUtils.substringAfterLast("a", "z")     = ""
        Parameters:
        str - the String to get a substring from, may be null
        separator - the String to search for, may be null
        Returns:
        the substring after the last occurrence of the separator, null if null String input
        Since:
        2.0

      • substringBefore

        public static java.lang.String substringBefore​(java.lang.String str,
                                               int separator)

        Gets the substring before the first occurrence of a separator. The separator is not returned.

        A null string input will return null. An empty ("") string input will return the empty string.

        If nothing is found, the string input is returned. 

         StringUtils.substringBefore(null, *)      = null
 StringUtils.substringBefore("", *)        = ""
 StringUtils.substringBefore("abc", 'a')   = ""
 StringUtils.substringBefore("abcba", 'b') = "a"
 StringUtils.substringBefore("abc", 'c')   = "ab"
 StringUtils.substringBefore("abc", 'd')   = "abc"
        Parameters:
        str - the String to get a substring from, may be null
        separator - the String to search for, may be null
        Returns:
        the substring before the first occurrence of the separator, null if null String input
        Since:
        3.12.0

      • substringBefore

        public static java.lang.String substringBefore​(java.lang.String str,
                                               java.lang.String separator)

        Gets the substring before the first occurrence of a separator. The separator is not returned.

        A null string input will return null. An empty ("") string input will return the empty string. A null separator will return the input string.

        If nothing is found, the string input is returned. 

         StringUtils.substringBefore(null, *)      = null
 StringUtils.substringBefore("", *)        = ""
 StringUtils.substringBefore("abc", "a")   = ""
 StringUtils.substringBefore("abcba", "b") = "a"
 StringUtils.substringBefore("abc", "c")   = "ab"
 StringUtils.substringBefore("abc", "d")   = "abc"
 StringUtils.substringBefore("abc", "")    = ""
 StringUtils.substringBefore("abc", null)  = "abc"
        Parameters:
        str - the String to get a substring from, may be null
        separator - the String to search for, may be null
        Returns:
        the substring before the first occurrence of the separator, null if null String input
        Since:
        2.0

      • substringBeforeLast

        public static java.lang.String substringBeforeLast​(java.lang.String str,
                                                   java.lang.String separator)

        Gets the substring before the last occurrence of a separator. The separator is not returned.

        A null string input will return null. An empty ("") string input will return the empty string. An empty or null separator will return the input string.

        If nothing is found, the string input is returned. 

         StringUtils.substringBeforeLast(null, *)      = null
 StringUtils.substringBeforeLast("", *)        = ""
 StringUtils.substringBeforeLast("abcba", "b") = "abc"
 StringUtils.substringBeforeLast("abc", "c")   = "ab"
 StringUtils.substringBeforeLast("a", "a")     = ""
 StringUtils.substringBeforeLast("a", "z")     = "a"
 StringUtils.substringBeforeLast("a", null)    = "a"
 StringUtils.substringBeforeLast("a", "")      = "a"
        Parameters:
        str - the String to get a substring from, may be null
        separator - the String to search for, may be null
        Returns:
        the substring before the last occurrence of the separator, null if null String input
        Since:
        2.0

      • substringBetween

        public static java.lang.String substringBetween​(java.lang.String str,
                                                java.lang.String tag)

        Gets the String that is nested in between two instances of the same String.

        A null input String returns null. A null tag returns null. 

         StringUtils.substringBetween(null, *)            = null
 StringUtils.substringBetween("", "")             = ""
 StringUtils.substringBetween("", "tag")          = null
 StringUtils.substringBetween("tagabctag", null)  = null
 StringUtils.substringBetween("tagabctag", "")    = ""
 StringUtils.substringBetween("tagabctag", "tag") = "abc"
        Parameters:
        str - the String containing the substring, may be null
        tag - the String before and after the substring, may be null
        Returns:
        the substring, null if no match
        Since:
        2.0

      • substringBetween

        public static java.lang.String substringBetween​(java.lang.String str,
                                                java.lang.String open,
                                                java.lang.String close)

        Gets the String that is nested in between two Strings. Only the first match is returned.

        A null input String returns null. A null open/close returns null (no match). An empty ("") open and close returns an empty string. 

         StringUtils.substringBetween("wx[b]yz", "[", "]") = "b"
 StringUtils.substringBetween(null, *, *)          = null
 StringUtils.substringBetween(*, null, *)          = null
 StringUtils.substringBetween(*, *, null)          = null
 StringUtils.substringBetween("", "", "")          = ""
 StringUtils.substringBetween("", "", "]")         = null
 StringUtils.substringBetween("", "[", "]")        = null
 StringUtils.substringBetween("yabcz", "", "")     = ""
 StringUtils.substringBetween("yabcz", "y", "z")   = "abc"
 StringUtils.substringBetween("yabczyabcz", "y", "z")   = "abc"
        Parameters:
        str - the String containing the substring, may be null
        open - the String before the substring, may be null
        close - the String after the substring, may be null
        Returns:
        the substring, null if no match
        Since:
        2.0

      • substringsBetween

        public static java.lang.String[] substringsBetween​(java.lang.String str,
                                                   java.lang.String open,
                                                   java.lang.String close)

        Searches a String for substrings delimited by a start and end tag, returning all matching substrings in an array.

        A null input String returns null. A null open/close returns null (no match). An empty ("") open/close returns null (no match). 

         StringUtils.substringsBetween("[a][b][c]", "[", "]") = ["a","b","c"]
 StringUtils.substringsBetween(null, *, *)            = null
 StringUtils.substringsBetween(*, null, *)            = null
 StringUtils.substringsBetween(*, *, null)            = null
 StringUtils.substringsBetween("", "[", "]")          = []
        Parameters:
        str - the String containing the substrings, null returns null, empty returns empty
        open - the String identifying the start of the substring, empty returns null
        close - the String identifying the end of the substring, empty returns null
        Returns:
        a String Array of substrings, or null if no match
        Since:
        2.3

      • swapCase

        public static java.lang.String swapCase​(java.lang.String str)

        Swaps the case of a String changing upper and title case to lower case, and lower case to upper case.

        • Upper case character converts to Lower case
        • Title case character converts to Lower case
        • Lower case character converts to Upper case

        For a word based algorithm, see WordUtils.swapCase(String). A null input String returns null. 

         StringUtils.swapCase(null)                 = null
 StringUtils.swapCase("")                   = ""
 StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"

        NOTE: This method changed in Lang version 2.0. It no longer performs a word based algorithm. If you only use ASCII, you will notice no change. That functionality is available in org.apache.commons.lang3.text.WordUtils.

        Parameters:
        str - the String to swap case, may be null
        Returns:
        the changed String, null if null String input

      • toCodePoints

        public static int[] toCodePoints​(java.lang.CharSequence cs)

        Converts a CharSequence into an array of code points.

        Valid pairs of surrogate code units will be converted into a single supplementary code point. Isolated surrogate code units (i.e. a high surrogate not followed by a low surrogate or a low surrogate not preceded by a high surrogate) will be returned as-is. 

         StringUtils.toCodePoints(null)   =  null
 StringUtils.toCodePoints("")     =  []  // empty array
        Parameters:
        cs - the character sequence to convert
        Returns:
        an array of code points
        Since:
        3.6

      • toEncodedString

        public static java.lang.String toEncodedString​(byte[] bytes,
                                               java.nio.charset.Charset charset)
        Converts a byte[] to a String using the specified character encoding.
        Parameters:
        bytes - the byte array to read from
        charset - the encoding to use, if null then use the platform default
        Returns:
        a new String
        Throws:
        java.lang.NullPointerException - if bytes is null
        Since:
        3.2, 3.3 No longer throws UnsupportedEncodingException.

      • toRootLowerCase

        public static java.lang.String toRootLowerCase​(java.lang.String source)
        Converts the given source String as a lower-case using the Locale.ROOT locale in a null-safe manner.
        Parameters:
        source - A source String or null.
        Returns:
        the given source String as a lower-case using the Locale.ROOT locale or null.
        Since:
        3.10

      • toRootUpperCase

        public static java.lang.String toRootUpperCase​(java.lang.String source)
        Converts the given source String as a upper-case using the Locale.ROOT locale in a null-safe manner.
        Parameters:
        source - A source String or null.
        Returns:
        the given source String as a upper-case using the Locale.ROOT locale or null.
        Since:
        3.10

      • toString

        @Deprecated
public static java.lang.String toString​(byte[] bytes,
                                        java.lang.String charsetName)
                                 throws java.io.UnsupportedEncodingException
        Deprecated.
        use toEncodedString(byte[], Charset) instead of String constants in your code
        Converts a byte[] to a String using the specified character encoding.
        Parameters:
        bytes - the byte array to read from
        charsetName - the encoding to use, if null then use the platform default
        Returns:
        a new String
        Throws:
        java.io.UnsupportedEncodingException - If the named charset is not supported
        java.lang.NullPointerException - if the input is null
        Since:
        3.1

      • trim

        public static java.lang.String trim​(java.lang.String str)

        Removes control characters (char <= 32) from both ends of this String, handling null by returning null.

        The String is trimmed using String.trim(). Trim removes start and end characters <= 32. To strip whitespace use strip(String).

        To trim your choice of characters, use the strip(String, String) methods. 

         StringUtils.trim(null)          = null
 StringUtils.trim("")            = ""
 StringUtils.trim("     ")       = ""
 StringUtils.trim("abc")         = "abc"
 StringUtils.trim("    abc    ") = "abc"
        Parameters:
        str - the String to be trimmed, may be null
        Returns:
        the trimmed string, null if null String input

      • trimToEmpty

        public static java.lang.String trimToEmpty​(java.lang.String str)

        Removes control characters (char <= 32) from both ends of this String returning an empty String ("") if the String is empty ("") after the trim or if it is null.

        The String is trimmed using String.trim(). Trim removes start and end characters <= 32. To strip whitespace use stripToEmpty(String). 

         StringUtils.trimToEmpty(null)          = ""
 StringUtils.trimToEmpty("")            = ""
 StringUtils.trimToEmpty("     ")       = ""
 StringUtils.trimToEmpty("abc")         = "abc"
 StringUtils.trimToEmpty("    abc    ") = "abc"
        Parameters:
        str - the String to be trimmed, may be null
        Returns:
        the trimmed String, or an empty String if null input
        Since:
        2.0

      • trimToNull

        public static java.lang.String trimToNull​(java.lang.String str)

        Removes control characters (char <= 32) from both ends of this String returning null if the String is empty ("") after the trim or if it is null.

        The String is trimmed using String.trim(). Trim removes start and end characters <= 32. To strip whitespace use stripToNull(String). 

         StringUtils.trimToNull(null)          = null
 StringUtils.trimToNull("")            = null
 StringUtils.trimToNull("     ")       = null
 StringUtils.trimToNull("abc")         = "abc"
 StringUtils.trimToNull("    abc    ") = "abc"
        Parameters:
        str - the String to be trimmed, may be null
        Returns:
        the trimmed String, null if only chars <= 32, empty or null String input
        Since:
        2.0

      • truncate

        public static java.lang.String truncate​(java.lang.String str,
                                        int maxWidth)

        Truncates a String. This will turn "Now is the time for all good men" into "Now is the time for".

        Specifically:

        • If str is less than maxWidth characters long, return it.
        • Else truncate it to substring(str, 0, maxWidth).
        • If maxWidth is less than 0, throw an IllegalArgumentException.
        • In no case will it return a String of length greater than maxWidth.
         StringUtils.truncate(null, 0)       = null
 StringUtils.truncate(null, 2)       = null
 StringUtils.truncate("", 4)         = ""
 StringUtils.truncate("abcdefg", 4)  = "abcd"
 StringUtils.truncate("abcdefg", 6)  = "abcdef"
 StringUtils.truncate("abcdefg", 7)  = "abcdefg"
 StringUtils.truncate("abcdefg", 8)  = "abcdefg"
 StringUtils.truncate("abcdefg", -1) = throws an IllegalArgumentException
        Parameters:
        str - the String to truncate, may be null
        maxWidth - maximum length of result String, must be positive
        Returns:
        truncated String, null if null String input
        Throws:
        java.lang.IllegalArgumentException - If maxWidth is less than 0
        Since:
        3.5

      • truncate

        public static java.lang.String truncate​(java.lang.String str,
                                        int offset,
                                        int maxWidth)

        Truncates a String. This will turn "Now is the time for all good men" into "is the time for all".

        Works like truncate(String, int), but allows you to specify a "left edge" offset.

        Specifically:

        • If str is less than maxWidth characters long, return it.
        • Else truncate it to substring(str, offset, maxWidth).
        • If maxWidth is less than 0, throw an IllegalArgumentException.
        • If offset is less than 0, throw an IllegalArgumentException.
        • In no case will it return a String of length greater than maxWidth.
         StringUtils.truncate(null, 0, 0) = null
 StringUtils.truncate(null, 2, 4) = null
 StringUtils.truncate("", 0, 10) = ""
 StringUtils.truncate("", 2, 10) = ""
 StringUtils.truncate("abcdefghij", 0, 3) = "abc"
 StringUtils.truncate("abcdefghij", 5, 6) = "fghij"
 StringUtils.truncate("raspberry peach", 10, 15) = "peach"
 StringUtils.truncate("abcdefghijklmno", 0, 10) = "abcdefghij"
 StringUtils.truncate("abcdefghijklmno", -1, 10) = throws an IllegalArgumentException
 StringUtils.truncate("abcdefghijklmno", Integer.MIN_VALUE, 10) = throws an IllegalArgumentException
 StringUtils.truncate("abcdefghijklmno", Integer.MIN_VALUE, Integer.MAX_VALUE) = throws an IllegalArgumentException
 StringUtils.truncate("abcdefghijklmno", 0, Integer.MAX_VALUE) = "abcdefghijklmno"
 StringUtils.truncate("abcdefghijklmno", 1, 10) = "bcdefghijk"
 StringUtils.truncate("abcdefghijklmno", 2, 10) = "cdefghijkl"
 StringUtils.truncate("abcdefghijklmno", 3, 10) = "defghijklm"
 StringUtils.truncate("abcdefghijklmno", 4, 10) = "efghijklmn"
 StringUtils.truncate("abcdefghijklmno", 5, 10) = "fghijklmno"
 StringUtils.truncate("abcdefghijklmno", 5, 5) = "fghij"
 StringUtils.truncate("abcdefghijklmno", 5, 3) = "fgh"
 StringUtils.truncate("abcdefghijklmno", 10, 3) = "klm"
 StringUtils.truncate("abcdefghijklmno", 10, Integer.MAX_VALUE) = "klmno"
 StringUtils.truncate("abcdefghijklmno", 13, 1) = "n"
 StringUtils.truncate("abcdefghijklmno", 13, Integer.MAX_VALUE) = "no"
 StringUtils.truncate("abcdefghijklmno", 14, 1) = "o"
 StringUtils.truncate("abcdefghijklmno", 14, Integer.MAX_VALUE) = "o"
 StringUtils.truncate("abcdefghijklmno", 15, 1) = ""
 StringUtils.truncate("abcdefghijklmno", 15, Integer.MAX_VALUE) = ""
 StringUtils.truncate("abcdefghijklmno", Integer.MAX_VALUE, Integer.MAX_VALUE) = ""
 StringUtils.truncate("abcdefghij", 3, -1) = throws an IllegalArgumentException
 StringUtils.truncate("abcdefghij", -2, 4) = throws an IllegalArgumentException
        Parameters:
        str - the String to truncate, may be null
        offset - left edge of source String
        maxWidth - maximum length of result String, must be positive
        Returns:
        truncated String, null if null String input
        Throws:
        java.lang.IllegalArgumentException - If offset or maxWidth is less than 0
        Since:
        3.5

      • uncapitalize

        public static java.lang.String uncapitalize​(java.lang.String str)

        Uncapitalizes a String, changing the first character to lower case as per Character.toLowerCase(int). No other characters are changed.

        For a word based algorithm, see WordUtils.uncapitalize(String). A null input String returns null. 

         StringUtils.uncapitalize(null)  = null
 StringUtils.uncapitalize("")    = ""
 StringUtils.uncapitalize("cat") = "cat"
 StringUtils.uncapitalize("Cat") = "cat"
 StringUtils.uncapitalize("CAT") = "cAT"
        Parameters:
        str - the String to uncapitalize, may be null
        Returns:
        the uncapitalized String, null if null String input
        Since:
        2.0
        See Also:
        WordUtils.uncapitalize(String), capitalize(String)

      • unwrap

        public static java.lang.String unwrap​(java.lang.String str,
                                      char wrapChar)

        Unwraps a given string from a character. 

         StringUtils.unwrap(null, null)         = null
 StringUtils.unwrap(null, '\0')         = null
 StringUtils.unwrap(null, '1')          = null
 StringUtils.unwrap("a", 'a')           = "a"
 StringUtils.unwrap("aa", 'a')           = ""
 StringUtils.unwrap("\'abc\'", '\'')    = "abc"
 StringUtils.unwrap("AABabcBAA", 'A')   = "ABabcBA"
 StringUtils.unwrap("A", '#')           = "A"
 StringUtils.unwrap("#A", '#')          = "#A"
 StringUtils.unwrap("A#", '#')          = "A#"
        Parameters:
        str - the String to be unwrapped, can be null
        wrapChar - the character used to unwrap
        Returns:
        unwrapped String or the original string if it is not quoted properly with the wrapChar
        Since:
        3.6

      • unwrap

        public static java.lang.String unwrap​(java.lang.String str,
                                      java.lang.String wrapToken)

        Unwraps a given string from anther string. 

         StringUtils.unwrap(null, null)         = null
 StringUtils.unwrap(null, "")           = null
 StringUtils.unwrap(null, "1")          = null
 StringUtils.unwrap("a", "a")           = "a"
 StringUtils.unwrap("aa", "a")          = ""
 StringUtils.unwrap("\'abc\'", "\'")    = "abc"
 StringUtils.unwrap("\"abc\"", "\"")    = "abc"
 StringUtils.unwrap("AABabcBAA", "AA")  = "BabcB"
 StringUtils.unwrap("A", "#")           = "A"
 StringUtils.unwrap("#A", "#")          = "#A"
 StringUtils.unwrap("A#", "#")          = "A#"
        Parameters:
        str - the String to be unwrapped, can be null
        wrapToken - the String used to unwrap
        Returns:
        unwrapped String or the original string if it is not quoted properly with the wrapToken
        Since:
        3.6

      • upperCase

        public static java.lang.String upperCase​(java.lang.String str)

        Converts a String to upper case as per String.toUpperCase().

        A null input String returns null. 

         StringUtils.upperCase(null)  = null
 StringUtils.upperCase("")    = ""
 StringUtils.upperCase("aBc") = "ABC"

        Note: As described in the documentation for String.toUpperCase(), the result of this method is affected by the current locale. For platform-independent case transformations, the method lowerCase(String, Locale) should be used with a specific locale (e.g. Locale.ENGLISH).

        Parameters:
        str - the String to upper case, may be null
        Returns:
        the upper cased String, null if null String input

      • upperCase

        public static java.lang.String upperCase​(java.lang.String str,
                                         java.util.Locale locale)

        Converts a String to upper case as per String.toUpperCase(Locale).

        A null input String returns null. 

         StringUtils.upperCase(null, Locale.ENGLISH)  = null
 StringUtils.upperCase("", Locale.ENGLISH)    = ""
 StringUtils.upperCase("aBc", Locale.ENGLISH) = "ABC"
        Parameters:
        str - the String to upper case, may be null
        locale - the locale that defines the case transformation rules, must not be null
        Returns:
        the upper cased String, null if null String input
        Since:
        2.5

      • valueOf

        public static java.lang.String valueOf​(char[] value)
        Returns the string representation of the char array or null.
        Parameters:
        value - the character array.
        Returns:
        a String or null
        Since:
        3.9
        See Also:
        String.valueOf(char[])

      • wrap

        public static java.lang.String wrap​(java.lang.String str,
                                    char wrapWith)

        Wraps a string with a char. 

         StringUtils.wrap(null, *)        = null
 StringUtils.wrap("", *)          = ""
 StringUtils.wrap("ab", '\0')     = "ab"
 StringUtils.wrap("ab", 'x')      = "xabx"
 StringUtils.wrap("ab", '\'')     = "'ab'"
 StringUtils.wrap("\"ab\"", '\"') = "\"\"ab\"\""
        Parameters:
        str - the string to be wrapped, may be null
        wrapWith - the char that will wrap str
        Returns:
        the wrapped string, or null if str==null
        Since:
        3.4

      • wrap

        public static java.lang.String wrap​(java.lang.String str,
                                    java.lang.String wrapWith)

        Wraps a String with another String.

        A null input String returns null. 

         StringUtils.wrap(null, *)         = null
 StringUtils.wrap("", *)           = ""
 StringUtils.wrap("ab", null)      = "ab"
 StringUtils.wrap("ab", "x")       = "xabx"
 StringUtils.wrap("ab", "\"")      = "\"ab\""
 StringUtils.wrap("\"ab\"", "\"")  = "\"\"ab\"\""
 StringUtils.wrap("ab", "'")       = "'ab'"
 StringUtils.wrap("'abcd'", "'")   = "''abcd''"
 StringUtils.wrap("\"abcd\"", "'") = "'\"abcd\"'"
 StringUtils.wrap("'abcd'", "\"")  = "\"'abcd'\""
        Parameters:
        str - the String to be wrapper, may be null
        wrapWith - the String that will wrap str
        Returns:
        wrapped String, null if null String input
        Since:
        3.4

      • wrapIfMissing

        public static java.lang.String wrapIfMissing​(java.lang.String str,
                                             char wrapWith)

        Wraps a string with a char if that char is missing from the start or end of the given string.

        A new String will not be created if str is already wrapped. 

         StringUtils.wrapIfMissing(null, *)        = null
 StringUtils.wrapIfMissing("", *)          = ""
 StringUtils.wrapIfMissing("ab", '\0')     = "ab"
 StringUtils.wrapIfMissing("ab", 'x')      = "xabx"
 StringUtils.wrapIfMissing("ab", '\'')     = "'ab'"
 StringUtils.wrapIfMissing("\"ab\"", '\"') = "\"ab\""
 StringUtils.wrapIfMissing("/", '/')  = "/"
 StringUtils.wrapIfMissing("a/b/c", '/')  = "/a/b/c/"
 StringUtils.wrapIfMissing("/a/b/c", '/')  = "/a/b/c/"
 StringUtils.wrapIfMissing("a/b/c/", '/')  = "/a/b/c/"
        Parameters:
        str - the string to be wrapped, may be null
        wrapWith - the char that will wrap str
        Returns:
        the wrapped string, or null if str==null
        Since:
        3.5

      • wrapIfMissing

        public static java.lang.String wrapIfMissing​(java.lang.String str,
                                             java.lang.String wrapWith)

        Wraps a string with a string if that string is missing from the start or end of the given string.

        A new String will not be created if str is already wrapped. 

         StringUtils.wrapIfMissing(null, *)         = null
 StringUtils.wrapIfMissing("", *)           = ""
 StringUtils.wrapIfMissing("ab", null)      = "ab"
 StringUtils.wrapIfMissing("ab", "x")       = "xabx"
 StringUtils.wrapIfMissing("ab", "\"")      = "\"ab\""
 StringUtils.wrapIfMissing("\"ab\"", "\"")  = "\"ab\""
 StringUtils.wrapIfMissing("ab", "'")       = "'ab'"
 StringUtils.wrapIfMissing("'abcd'", "'")   = "'abcd'"
 StringUtils.wrapIfMissing("\"abcd\"", "'") = "'\"abcd\"'"
 StringUtils.wrapIfMissing("'abcd'", "\"")  = "\"'abcd'\""
 StringUtils.wrapIfMissing("/", "/")  = "/"
 StringUtils.wrapIfMissing("a/b/c", "/")  = "/a/b/c/"
 StringUtils.wrapIfMissing("/a/b/c", "/")  = "/a/b/c/"
 StringUtils.wrapIfMissing("a/b/c/", "/")  = "/a/b/c/"
        Parameters:
        str - the string to be wrapped, may be null
        wrapWith - the string that will wrap str
        Returns:
        the wrapped string, or null if str==null
        Since:
        3.5