Class ByteBuf

  • All Implemented Interfaces:
    java.lang.Comparable<ByteBuf>
    Direct Known Subclasses:
    AbstractByteBuf, PacketBuffer, SwappedByteBuf

    public abstract class ByteBuf
    extends java.lang.Object
    implements java.lang.Comparable<ByteBuf>
    A random and sequential accessible sequence of zero or more bytes (octets). This interface provides an abstract view for one or more primitive byte arrays (byte[]) and NIO buffers.

    Creation of a buffer

    It is recommended to create a new buffer using the helper methods in Unpooled rather than calling an individual implementation's constructor.

    Random Access Indexing

    Just like an ordinary primitive byte array, ByteBuf uses zero-based indexing. It means the index of the first byte is always 0 and the index of the last byte is always capacity - 1. For example, to iterate all bytes of a buffer, you can do the following, regardless of its internal implementation:
     ByteBuf buffer = ...;
     for (int i = 0; i < buffer.capacity(); i ++) {
         byte b = buffer.getByte(i);
         System.out.println((char) b);
     }
     

    Sequential Access Indexing

    ByteBuf provides two pointer variables to support sequential read and write operations - readerIndex for a read operation and writerIndex for a write operation respectively. The following diagram shows how a buffer is segmented into three areas by the two pointers:
          +-------------------+------------------+------------------+
          | discardable bytes |  readable bytes  |  writable bytes  |
          |                   |     (CONTENT)    |                  |
          +-------------------+------------------+------------------+
          |                   |                  |                  |
          0      <=      readerIndex   <=   writerIndex    <=    capacity
     

    Readable bytes (the actual content)

    This segment is where the actual data is stored. Any operation whose name starts with read or skip will get or skip the data at the current readerIndex and increase it by the number of read bytes. If the argument of the read operation is also a ByteBuf and no destination index is specified, the specified buffer's writerIndex is increased together.

    If there's not enough content left, IndexOutOfBoundsException is raised. The default value of newly allocated, wrapped or copied buffer's readerIndex is 0.

     // Iterates the readable bytes of a buffer.
     ByteBuf buffer = ...;
     while (buffer.isReadable()) {
         System.out.println(buffer.readByte());
     }
     

    Writable bytes

    This segment is a undefined space which needs to be filled. Any operation whose name starts with write will write the data at the current writerIndex and increase it by the number of written bytes. If the argument of the write operation is also a ByteBuf, and no source index is specified, the specified buffer's readerIndex is increased together.

    If there's not enough writable bytes left, IndexOutOfBoundsException is raised. The default value of newly allocated buffer's writerIndex is 0. The default value of wrapped or copied buffer's writerIndex is the capacity of the buffer.

     // Fills the writable bytes of a buffer with random integers.
     ByteBuf buffer = ...;
     while (buffer.maxWritableBytes() >= 4) {
         buffer.writeInt(random.nextInt());
     }
     

    Discardable bytes

    This segment contains the bytes which were read already by a read operation. Initially, the size of this segment is 0, but its size increases up to the writerIndex as read operations are executed. The read bytes can be discarded by calling discardReadBytes() to reclaim unused area as depicted by the following diagram:
      BEFORE discardReadBytes()
    
          +-------------------+------------------+------------------+
          | discardable bytes |  readable bytes  |  writable bytes  |
          +-------------------+------------------+------------------+
          |                   |                  |                  |
          0      <=      readerIndex   <=   writerIndex    <=    capacity
    
    
      AFTER discardReadBytes()
    
          +------------------+--------------------------------------+
          |  readable bytes  |    writable bytes (got more space)   |
          +------------------+--------------------------------------+
          |                  |                                      |
     readerIndex (0) <= writerIndex (decreased)        <=        capacity
     
    Please note that there is no guarantee about the content of writable bytes after calling discardReadBytes(). The writable bytes will not be moved in most cases and could even be filled with completely different data depending on the underlying buffer implementation.

    Clearing the buffer indexes

    You can set both readerIndex and writerIndex to 0 by calling clear(). It does not clear the buffer content (e.g. filling with 0) but just clears the two pointers. Please also note that the semantic of this operation is different from ByteBuffer.clear().
      BEFORE clear()
    
          +-------------------+------------------+------------------+
          | discardable bytes |  readable bytes  |  writable bytes  |
          +-------------------+------------------+------------------+
          |                   |                  |                  |
          0      <=      readerIndex   <=   writerIndex    <=    capacity
    
    
      AFTER clear()
    
          +---------------------------------------------------------+
          |             writable bytes (got more space)             |
          +---------------------------------------------------------+
          |                                                         |
          0 = readerIndex = writerIndex            <=            capacity
     

    Search operations

    For simple single-byte searches, use indexOf(int, int, byte) and bytesBefore(int, int, byte). bytesBefore(byte) is especially useful when you deal with a NUL-terminated string. For complicated searches, use #forEachByte(int, int, ByteBufProcessor) with a ByteBufProcessor implementation.

    Mark and reset

    There are two marker indexes in every buffer. One is for storing readerIndex and the other is for storing writerIndex. You can always reposition one of the two indexes by calling a reset method. It works in a similar fashion to the mark and reset methods in InputStream except that there's no readlimit.

    Derived buffers

    You can create a view of an existing buffer by calling either duplicate(), slice() or slice(int, int). A derived buffer will have an independent readerIndex, writerIndex and marker indexes, while it shares other internal data representation, just like a NIO buffer does.

    In case a completely fresh copy of an existing buffer is required, please call copy() method instead.

    Also be aware that obtaining derived buffers will NOT call #retain() and so the reference count will NOT be increased.

    Conversion to existing JDK types

    Byte array

    If a ByteBuf is backed by a byte array (i.e. byte[]), you can access it directly via the array() method. To determine if a buffer is backed by a byte array, hasArray() should be used.

    NIO Buffers

    If a ByteBuf can be converted into an NIO ByteBuffer which shares its content (i.e. view buffer), you can get it via the nioBuffer() method. To determine if a buffer can be converted into an NIO buffer, use nioBufferCount().

    Strings

    Various toString(Charset) methods convert a ByteBuf into a String. Please note that toString() is not a conversion method.

    I/O Streams

    Please refer to ByteBufInputStream and ByteBufOutputStream.
    • Constructor Summary

      Constructors 
      Constructor Description
      ByteBuf()  
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      static ByteBuf allocate​(int length, int maxLength)  
      static ByteBuf allocate​(java.nio.ByteBuffer data, int maxLength)  
      abstract byte[] array()
      Returns the backing byte array of this buffer.
      abstract int arrayOffset()
      Returns the offset of the first byte within the backing byte array of this buffer.
      abstract int bytesBefore​(byte value)
      Locates the first occurrence of the specified value in this buffer.
      abstract int bytesBefore​(int length, byte value)
      Locates the first occurrence of the specified value in this buffer.
      abstract int bytesBefore​(int index, int length, byte value)
      Locates the first occurrence of the specified value in this buffer.
      abstract int capacity()
      Returns the number of bytes (octets) this buffer can contain.
      abstract ByteBuf capacity​(int newCapacity)
      Adjusts the capacity of this buffer.
      abstract ByteBuf clear()
      Sets the readerIndex and writerIndex of this buffer to 0.
      abstract int compareTo​(ByteBuf buffer)
      Compares the content of the specified buffer to the content of this buffer.
      abstract ByteBuf copy()
      Returns a copy of this buffer's readable bytes.
      abstract ByteBuf copy​(int index, int length)
      Returns a copy of this buffer's sub-region.
      abstract ByteBuf discardReadBytes()
      Discards the bytes between the 0th index and readerIndex.
      abstract ByteBuf discardSomeReadBytes()
      Similar to discardReadBytes() except that this method might discard some, all, or none of read bytes depending on its internal implementation to reduce overall memory bandwidth consumption at the cost of potentially additional memory consumption.
      abstract ByteBuf duplicate()
      Returns a buffer which shares the whole region of this buffer.
      abstract ByteBuf ensureWritable​(int minWritableBytes)
      Makes sure the number of the writable bytes is equal to or greater than the specified value.
      abstract int ensureWritable​(int minWritableBytes, boolean force)
      Tries to make sure the number of the writable bytes is equal to or greater than the specified value.
      abstract boolean equals​(java.lang.Object obj)
      Determines if the content of the specified buffer is identical to the content of this array.
      abstract boolean getBoolean​(int index)
      Gets a boolean at the specified absolute (@code index) in this buffer.
      abstract byte getByte​(int index)
      Gets a byte at the specified absolute index in this buffer.
      abstract ByteBuf getBytes​(int index, byte[] dst)
      Transfers this buffer's data to the specified destination starting at the specified absolute index.
      abstract ByteBuf getBytes​(int index, byte[] dst, int dstIndex, int length)
      Transfers this buffer's data to the specified destination starting at the specified absolute index.
      abstract ByteBuf getBytes​(int index, java.io.OutputStream out, int length)
      Transfers this buffer's data to the specified stream starting at the specified absolute index.
      abstract ByteBuf getBytes​(int index, java.nio.ByteBuffer dst)
      Transfers this buffer's data to the specified destination starting at the specified absolute index until the destination's position reaches its limit.
      abstract ByteBuf getBytes​(int index, ByteBuf dst)
      Transfers this buffer's data to the specified destination starting at the specified absolute index until the destination becomes non-writable.
      abstract ByteBuf getBytes​(int index, ByteBuf dst, int length)
      Transfers this buffer's data to the specified destination starting at the specified absolute index.
      abstract ByteBuf getBytes​(int index, ByteBuf dst, int dstIndex, int length)
      Transfers this buffer's data to the specified destination starting at the specified absolute index.
      abstract char getChar​(int index)
      Gets a 2-byte UTF-16 character at the specified absolute index in this buffer.
      abstract double getDouble​(int index)
      Gets a 64-bit floating point number at the specified absolute index in this buffer.
      abstract float getFloat​(int index)
      Gets a 32-bit floating point number at the specified absolute index in this buffer.
      abstract int getInt​(int index)
      Gets a 32-bit integer at the specified absolute index in this buffer.
      abstract long getLong​(int index)
      Gets a 64-bit long integer at the specified absolute index in this buffer.
      abstract int getMedium​(int index)
      Gets a 24-bit medium integer at the specified absolute index in this buffer.
      abstract short getShort​(int index)
      Gets a 16-bit short integer at the specified absolute index in this buffer.
      abstract short getUnsignedByte​(int index)
      Gets an unsigned byte at the specified absolute index in this buffer.
      abstract long getUnsignedInt​(int index)
      Gets an unsigned 32-bit integer at the specified absolute index in this buffer.
      abstract int getUnsignedMedium​(int index)
      Gets an unsigned 24-bit medium integer at the specified absolute index in this buffer.
      abstract int getUnsignedShort​(int index)
      Gets an unsigned 16-bit short integer at the specified absolute index in this buffer.
      abstract boolean hasArray()
      Returns true if and only if this buffer has a backing byte array.
      abstract int hashCode()
      Returns a hash code which was calculated from the content of this buffer.
      abstract boolean hasMemoryAddress()
      Returns true if and only if this buffer has a reference to the low-level memory address that points to the backing data.
      abstract int indexOf​(int fromIndex, int toIndex, byte value)
      Locates the first occurrence of the specified value in this buffer.
      abstract java.nio.ByteBuffer internalNioBuffer​(int index, int length)
      Internal use only: Exposes the internal NIO buffer.
      abstract boolean isDirect()
      Returns true if and only if this buffer is backed by an NIO direct buffer.
      abstract boolean isReadable()
      Returns true if and only if (this.writerIndex - this.readerIndex) is greater than 0.
      abstract boolean isReadable​(int size)
      Returns true if and only if this buffer contains equal to or more than the specified number of elements.
      abstract boolean isWritable()
      Returns true if and only if (this.capacity - this.writerIndex) is greater than 0.
      abstract boolean isWritable​(int size)
      Returns true if and only if this buffer has enough room to allow writing the specified number of elements.
      abstract ByteBuf markReaderIndex()
      Marks the current readerIndex in this buffer.
      abstract ByteBuf markWriterIndex()
      Marks the current writerIndex in this buffer.
      abstract int maxCapacity()
      Returns the maximum allowed capacity of this buffer.
      abstract int maxWritableBytes()
      Returns the maximum possible number of writable bytes, which is equal to (this.maxCapacity - this.writerIndex).
      abstract long memoryAddress()
      Returns the low-level memory address that point to the first byte of ths backing data.
      abstract java.nio.ByteBuffer nioBuffer()
      Exposes this buffer's readable bytes as an NIO ByteBuffer.
      abstract java.nio.ByteBuffer nioBuffer​(int index, int length)
      Exposes this buffer's sub-region as an NIO ByteBuffer.
      abstract int nioBufferCount()
      Returns the maximum number of NIO ByteBuffers that consist this buffer.
      abstract java.nio.ByteBuffer[] nioBuffers()
      Exposes this buffer's readable bytes as an NIO ByteBuffer's.
      abstract java.nio.ByteBuffer[] nioBuffers​(int index, int length)
      Exposes this buffer's bytes as an NIO ByteBuffer's for the specified index and length The returned buffer either share or contains the copied content of this buffer, while changing the position and limit of the returned NIO buffer does not affect the indexes and marks of this buffer.
      abstract java.nio.ByteOrder order()
      Returns the endianness of this buffer.
      abstract ByteBuf order​(java.nio.ByteOrder endianness)
      Returns a buffer with the specified endianness which shares the whole region, indexes, and marks of this buffer.
      abstract int readableBytes()
      Returns the number of readable bytes which is equal to (this.writerIndex - this.readerIndex).
      abstract boolean readBoolean()
      Gets a boolean at the current readerIndex and increases the readerIndex by 1 in this buffer.
      abstract byte readByte()
      Gets a byte at the current readerIndex and increases the readerIndex by 1 in this buffer.
      abstract ByteBuf readBytes​(byte[] dst)
      Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= dst.length).
      abstract ByteBuf readBytes​(byte[] dst, int dstIndex, int length)
      Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
      abstract ByteBuf readBytes​(int length)
      Transfers this buffer's data to a newly created buffer starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
      abstract ByteBuf readBytes​(java.io.OutputStream out, int length)
      Transfers this buffer's data to the specified stream starting at the current readerIndex.
      abstract ByteBuf readBytes​(java.nio.ByteBuffer dst)
      Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination's position reaches its limit, and increases the readerIndex by the number of the transferred bytes.
      abstract ByteBuf readBytes​(ByteBuf dst)
      Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination becomes non-writable, and increases the readerIndex by the number of the transferred bytes.
      abstract ByteBuf readBytes​(ByteBuf dst, int length)
      Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
      abstract ByteBuf readBytes​(ByteBuf dst, int dstIndex, int length)
      Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
      abstract char readChar()
      Gets a 2-byte UTF-16 character at the current readerIndex and increases the readerIndex by 2 in this buffer.
      abstract double readDouble()
      Gets a 64-bit floating point number at the current readerIndex and increases the readerIndex by 8 in this buffer.
      abstract int readerIndex()
      Returns the readerIndex of this buffer.
      abstract ByteBuf readerIndex​(int readerIndex)
      Sets the readerIndex of this buffer.
      abstract float readFloat()
      Gets a 32-bit floating point number at the current readerIndex and increases the readerIndex by 4 in this buffer.
      abstract int readInt()
      Gets a 32-bit integer at the current readerIndex and increases the readerIndex by 4 in this buffer.
      abstract long readLong()
      Gets a 64-bit integer at the current readerIndex and increases the readerIndex by 8 in this buffer.
      abstract int readMedium()
      Gets a 24-bit medium integer at the current readerIndex and increases the readerIndex by 3 in this buffer.
      abstract short readShort()
      Gets a 16-bit short integer at the current readerIndex and increases the readerIndex by 2 in this buffer.
      abstract ByteBuf readSlice​(int length)
      Returns a new slice of this buffer's sub-region starting at the current readerIndex and increases the readerIndex by the size of the new slice (= length).
      abstract short readUnsignedByte()
      Gets an unsigned byte at the current readerIndex and increases the readerIndex by 1 in this buffer.
      abstract long readUnsignedInt()
      Gets an unsigned 32-bit integer at the current readerIndex and increases the readerIndex by 4 in this buffer.
      abstract int readUnsignedMedium()
      Gets an unsigned 24-bit medium integer at the current readerIndex and increases the readerIndex by 3 in this buffer.
      abstract int readUnsignedShort()
      Gets an unsigned 16-bit short integer at the current readerIndex and increases the readerIndex by 2 in this buffer.
      abstract ByteBuf resetReaderIndex()
      Repositions the current readerIndex to the marked readerIndex in this buffer.
      abstract ByteBuf resetWriterIndex()
      Repositions the current writerIndex to the marked writerIndex in this buffer.
      abstract ByteBuf setBoolean​(int index, boolean value)
      Sets the specified boolean at the specified absolute index in this buffer.
      abstract ByteBuf setByte​(int index, int value)
      Sets the specified byte at the specified absolute index in this buffer.
      abstract ByteBuf setBytes​(int index, byte[] src)
      Transfers the specified source array's data to this buffer starting at the specified absolute index.
      abstract ByteBuf setBytes​(int index, byte[] src, int srcIndex, int length)
      Transfers the specified source array's data to this buffer starting at the specified absolute index.
      abstract int setBytes​(int index, java.io.InputStream in, int length)
      Transfers the content of the specified source stream to this buffer starting at the specified absolute index.
      abstract ByteBuf setBytes​(int index, java.nio.ByteBuffer src)
      Transfers the specified source buffer's data to this buffer starting at the specified absolute index until the source buffer's position reaches its limit.
      abstract ByteBuf setBytes​(int index, ByteBuf src)
      Transfers the specified source buffer's data to this buffer starting at the specified absolute index until the source buffer becomes unreadable.
      abstract ByteBuf setBytes​(int index, ByteBuf src, int length)
      Transfers the specified source buffer's data to this buffer starting at the specified absolute index.
      abstract ByteBuf setBytes​(int index, ByteBuf src, int srcIndex, int length)
      Transfers the specified source buffer's data to this buffer starting at the specified absolute index.
      abstract ByteBuf setChar​(int index, int value)
      Sets the specified 2-byte UTF-16 character at the specified absolute index in this buffer.
      abstract ByteBuf setDouble​(int index, double value)
      Sets the specified 64-bit floating-point number at the specified absolute index in this buffer.
      abstract ByteBuf setFloat​(int index, float value)
      Sets the specified 32-bit floating-point number at the specified absolute index in this buffer.
      abstract ByteBuf setIndex​(int readerIndex, int writerIndex)
      Sets the readerIndex and writerIndex of this buffer in one shot.
      abstract ByteBuf setInt​(int index, int value)
      Sets the specified 32-bit integer at the specified absolute index in this buffer.
      abstract ByteBuf setLong​(int index, long value)
      Sets the specified 64-bit long integer at the specified absolute index in this buffer.
      abstract ByteBuf setMedium​(int index, int value)
      Sets the specified 24-bit medium integer at the specified absolute index in this buffer.
      abstract ByteBuf setShort​(int index, int value)
      Sets the specified 16-bit short integer at the specified absolute index in this buffer.
      abstract ByteBuf setZero​(int index, int length)
      Fills this buffer with NUL (0x00) starting at the specified absolute index.
      abstract ByteBuf skipBytes​(int length)
      Increases the current readerIndex by the specified length in this buffer.
      abstract ByteBuf slice()
      Returns a slice of this buffer's readable bytes.
      abstract ByteBuf slice​(int index, int length)
      Returns a slice of this buffer's sub-region.
      abstract java.lang.String toString()
      Returns the string representation of this buffer.
      abstract java.lang.String toString​(int index, int length, java.nio.charset.Charset charset)
      Decodes this buffer's sub-region into a string with the specified character set.
      abstract java.lang.String toString​(java.nio.charset.Charset charset)
      Decodes this buffer's readable bytes into a string with the specified character set name.
      abstract ByteBuf unwrap()
      Return the underlying buffer instance if this buffer is a wrapper of another buffer.
      abstract int writableBytes()
      Returns the number of writable bytes which is equal to (this.capacity - this.writerIndex).
      abstract ByteBuf writeBoolean​(boolean value)
      Sets the specified boolean at the current writerIndex and increases the writerIndex by 1 in this buffer.
      abstract ByteBuf writeByte​(int value)
      Sets the specified byte at the current writerIndex and increases the writerIndex by 1 in this buffer.
      abstract ByteBuf writeBytes​(byte[] src)
      Transfers the specified source array's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= src.length).
      abstract ByteBuf writeBytes​(byte[] src, int srcIndex, int length)
      Transfers the specified source array's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).
      abstract int writeBytes​(java.io.InputStream in, int length)
      Transfers the content of the specified stream to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes.
      abstract ByteBuf writeBytes​(java.nio.ByteBuffer src)
      Transfers the specified source buffer's data to this buffer starting at the current writerIndex until the source buffer's position reaches its limit, and increases the writerIndex by the number of the transferred bytes.
      abstract ByteBuf writeBytes​(ByteBuf src)
      Transfers the specified source buffer's data to this buffer starting at the current writerIndex until the source buffer becomes unreadable, and increases the writerIndex by the number of the transferred bytes.
      abstract ByteBuf writeBytes​(ByteBuf src, int length)
      Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).
      abstract ByteBuf writeBytes​(ByteBuf src, int srcIndex, int length)
      Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).
      abstract ByteBuf writeChar​(int value)
      Sets the specified 2-byte UTF-16 character at the current writerIndex and increases the writerIndex by 2 in this buffer.
      abstract ByteBuf writeDouble​(double value)
      Sets the specified 64-bit floating point number at the current writerIndex and increases the writerIndex by 8 in this buffer.
      abstract ByteBuf writeFloat​(float value)
      Sets the specified 32-bit floating point number at the current writerIndex and increases the writerIndex by 4 in this buffer.
      abstract ByteBuf writeInt​(int value)
      Sets the specified 32-bit integer at the current writerIndex and increases the writerIndex by 4 in this buffer.
      abstract ByteBuf writeLong​(long value)
      Sets the specified 64-bit long integer at the current writerIndex and increases the writerIndex by 8 in this buffer.
      abstract ByteBuf writeMedium​(int value)
      Sets the specified 24-bit medium integer at the current writerIndex and increases the writerIndex by 3 in this buffer.
      abstract int writerIndex()
      Returns the writerIndex of this buffer.
      abstract ByteBuf writerIndex​(int writerIndex)
      Sets the writerIndex of this buffer.
      abstract ByteBuf writeShort​(int value)
      Sets the specified 16-bit short integer at the current writerIndex and increases the writerIndex by 2 in this buffer.
      abstract ByteBuf writeZero​(int length)
      Fills this buffer with NUL (0x00) starting at the current writerIndex and increases the writerIndex by the specified length.
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
    • Constructor Detail

      • ByteBuf

        public ByteBuf()
    • Method Detail

      • allocate

        public static ByteBuf allocate​(int length,
                                       int maxLength)
      • allocate

        public static ByteBuf allocate​(java.nio.ByteBuffer data,
                                       int maxLength)
      • capacity

        public abstract int capacity()
        Returns the number of bytes (octets) this buffer can contain.
      • capacity

        public abstract ByteBuf capacity​(int newCapacity)
        Adjusts the capacity of this buffer. If the newCapacity is less than the current capacity, the content of this buffer is truncated. If the newCapacity is greater than the current capacity, the buffer is appended with unspecified data whose length is (newCapacity - currentCapacity).
      • maxCapacity

        public abstract int maxCapacity()
        Returns the maximum allowed capacity of this buffer. If a user attempts to increase the capacity of this buffer beyond the maximum capacity using capacity(int) or ensureWritable(int), those methods will raise an IllegalArgumentException.
      • order

        public abstract java.nio.ByteOrder order()
        Returns the endianness of this buffer.
      • order

        public abstract ByteBuf order​(java.nio.ByteOrder endianness)
        Returns a buffer with the specified endianness which shares the whole region, indexes, and marks of this buffer. Modifying the content, the indexes, or the marks of the returned buffer or this buffer affects each other's content, indexes, and marks. If the specified endianness is identical to this buffer's byte order, this method can return this. This method does not modify readerIndex or writerIndex of this buffer.
      • unwrap

        public abstract ByteBuf unwrap()
        Return the underlying buffer instance if this buffer is a wrapper of another buffer.
        Returns:
        null if this buffer is not a wrapper
      • isDirect

        public abstract boolean isDirect()
        Returns true if and only if this buffer is backed by an NIO direct buffer.
      • readerIndex

        public abstract int readerIndex()
        Returns the readerIndex of this buffer.
      • readerIndex

        public abstract ByteBuf readerIndex​(int readerIndex)
        Sets the readerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified readerIndex is less than 0 or greater than this.writerIndex
      • writerIndex

        public abstract int writerIndex()
        Returns the writerIndex of this buffer.
      • writerIndex

        public abstract ByteBuf writerIndex​(int writerIndex)
        Sets the writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified writerIndex is less than this.readerIndex or greater than this.capacity
      • setIndex

        public abstract ByteBuf setIndex​(int readerIndex,
                                         int writerIndex)
        Sets the readerIndex and writerIndex of this buffer in one shot. This method is useful when you have to worry about the invocation order of readerIndex(int) and writerIndex(int) methods. For example, the following code will fail:
         // Create a buffer whose readerIndex, writerIndex and capacity are
         // 0, 0 and 8 respectively.
         ByteBuf buf = Unpooled.buffer(8);
        
         // IndexOutOfBoundsException is thrown because the specified
         // readerIndex (2) cannot be greater than the current writerIndex (0).
         buf.readerIndex(2);
         buf.writerIndex(4);
         
        The following code will also fail:
         // Create a buffer whose readerIndex, writerIndex and capacity are
         // 0, 8 and 8 respectively.
         ByteBuf buf = Unpooled.wrappedBuffer(new byte[8]);
        
         // readerIndex becomes 8.
         buf.readLong();
        
         // IndexOutOfBoundsException is thrown because the specified
         // writerIndex (4) cannot be less than the current readerIndex (8).
         buf.writerIndex(4);
         buf.readerIndex(2);
         
        By contrast, this method guarantees that it never throws an IndexOutOfBoundsException as long as the specified indexes meet basic constraints, regardless what the current index values of the buffer are:
         // No matter what the current state of the buffer is, the following
         // call always succeeds as long as the capacity of the buffer is not
         // less than 4.
         buf.setIndex(2, 4);
         
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified readerIndex is less than 0, if the specified writerIndex is less than the specified readerIndex or if the specified writerIndex is greater than this.capacity
      • readableBytes

        public abstract int readableBytes()
        Returns the number of readable bytes which is equal to (this.writerIndex - this.readerIndex).
      • writableBytes

        public abstract int writableBytes()
        Returns the number of writable bytes which is equal to (this.capacity - this.writerIndex).
      • maxWritableBytes

        public abstract int maxWritableBytes()
        Returns the maximum possible number of writable bytes, which is equal to (this.maxCapacity - this.writerIndex).
      • isReadable

        public abstract boolean isReadable()
        Returns true if and only if (this.writerIndex - this.readerIndex) is greater than 0.
      • isReadable

        public abstract boolean isReadable​(int size)
        Returns true if and only if this buffer contains equal to or more than the specified number of elements.
      • isWritable

        public abstract boolean isWritable()
        Returns true if and only if (this.capacity - this.writerIndex) is greater than 0.
      • isWritable

        public abstract boolean isWritable​(int size)
        Returns true if and only if this buffer has enough room to allow writing the specified number of elements.
      • clear

        public abstract ByteBuf clear()
        Sets the readerIndex and writerIndex of this buffer to 0. This method is identical to setIndex(0, 0).

        Please note that the behavior of this method is different from that of NIO buffer, which sets the limit to the capacity of the buffer.

      • markReaderIndex

        public abstract ByteBuf markReaderIndex()
        Marks the current readerIndex in this buffer. You can reposition the current readerIndex to the marked readerIndex by calling resetReaderIndex(). The initial value of the marked readerIndex is 0.
      • resetReaderIndex

        public abstract ByteBuf resetReaderIndex()
        Repositions the current readerIndex to the marked readerIndex in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the current writerIndex is less than the marked readerIndex
      • markWriterIndex

        public abstract ByteBuf markWriterIndex()
        Marks the current writerIndex in this buffer. You can reposition the current writerIndex to the marked writerIndex by calling resetWriterIndex(). The initial value of the marked writerIndex is 0.
      • resetWriterIndex

        public abstract ByteBuf resetWriterIndex()
        Repositions the current writerIndex to the marked writerIndex in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the current readerIndex is greater than the marked writerIndex
      • discardReadBytes

        public abstract ByteBuf discardReadBytes()
        Discards the bytes between the 0th index and readerIndex. It moves the bytes between readerIndex and writerIndex to the 0th index, and sets readerIndex and writerIndex to 0 and oldWriterIndex - oldReaderIndex respectively.

        Please refer to the class documentation for more detailed explanation.

      • discardSomeReadBytes

        public abstract ByteBuf discardSomeReadBytes()
        Similar to discardReadBytes() except that this method might discard some, all, or none of read bytes depending on its internal implementation to reduce overall memory bandwidth consumption at the cost of potentially additional memory consumption.
      • ensureWritable

        public abstract ByteBuf ensureWritable​(int minWritableBytes)
        Makes sure the number of the writable bytes is equal to or greater than the specified value. If there is enough writable bytes in this buffer, this method returns with no side effect. Otherwise, it raises an IllegalArgumentException.
        Parameters:
        minWritableBytes - the expected minimum number of writable bytes
        Throws:
        java.lang.IndexOutOfBoundsException - if writerIndex() + minWritableBytes > maxCapacity()
      • ensureWritable

        public abstract int ensureWritable​(int minWritableBytes,
                                           boolean force)
        Tries to make sure the number of the writable bytes is equal to or greater than the specified value. Unlike ensureWritable(int), this method does not raise an exception but returns a code.
        Parameters:
        minWritableBytes - the expected minimum number of writable bytes
        force - When writerIndex() + minWritableBytes > maxCapacity():
        • true - the capacity of the buffer is expanded to maxCapacity()
        • false - the capacity of the buffer is unchanged
        Returns:
        0 if the buffer has enough writable bytes, and its capacity is unchanged. 1 if the buffer does not have enough bytes, and its capacity is unchanged. 2 if the buffer has enough writable bytes, and its capacity has been increased. 3 if the buffer does not have enough bytes, but its capacity has been increased to its maximum.
      • getBoolean

        public abstract boolean getBoolean​(int index)
        Gets a boolean at the specified absolute (@code index) in this buffer. This method does not modify the readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 1 is greater than this.capacity
      • getByte

        public abstract byte getByte​(int index)
        Gets a byte at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 1 is greater than this.capacity
      • getUnsignedByte

        public abstract short getUnsignedByte​(int index)
        Gets an unsigned byte at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 1 is greater than this.capacity
      • getShort

        public abstract short getShort​(int index)
        Gets a 16-bit short integer at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 2 is greater than this.capacity
      • getUnsignedShort

        public abstract int getUnsignedShort​(int index)
        Gets an unsigned 16-bit short integer at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 2 is greater than this.capacity
      • getMedium

        public abstract int getMedium​(int index)
        Gets a 24-bit medium integer at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 3 is greater than this.capacity
      • getUnsignedMedium

        public abstract int getUnsignedMedium​(int index)
        Gets an unsigned 24-bit medium integer at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 3 is greater than this.capacity
      • getInt

        public abstract int getInt​(int index)
        Gets a 32-bit integer at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 4 is greater than this.capacity
      • getUnsignedInt

        public abstract long getUnsignedInt​(int index)
        Gets an unsigned 32-bit integer at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 4 is greater than this.capacity
      • getLong

        public abstract long getLong​(int index)
        Gets a 64-bit long integer at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 8 is greater than this.capacity
      • getChar

        public abstract char getChar​(int index)
        Gets a 2-byte UTF-16 character at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 2 is greater than this.capacity
      • getFloat

        public abstract float getFloat​(int index)
        Gets a 32-bit floating point number at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 4 is greater than this.capacity
      • getDouble

        public abstract double getDouble​(int index)
        Gets a 64-bit floating point number at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 8 is greater than this.capacity
      • getBytes

        public abstract ByteBuf getBytes​(int index,
                                         ByteBuf dst)
        Transfers this buffer's data to the specified destination starting at the specified absolute index until the destination becomes non-writable. This method is basically same with getBytes(int, ByteBuf, int, int), except that this method increases the writerIndex of the destination by the number of the transferred bytes while getBytes(int, ByteBuf, int, int) does not. This method does not modify readerIndex or writerIndex of the source buffer (i.e. this).
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or if index + dst.writableBytes is greater than this.capacity
      • getBytes

        public abstract ByteBuf getBytes​(int index,
                                         ByteBuf dst,
                                         int length)
        Transfers this buffer's data to the specified destination starting at the specified absolute index. This method is basically same with getBytes(int, ByteBuf, int, int), except that this method increases the writerIndex of the destination by the number of the transferred bytes while getBytes(int, ByteBuf, int, int) does not. This method does not modify readerIndex or writerIndex of the source buffer (i.e. this).
        Parameters:
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0, if index + length is greater than this.capacity, or if length is greater than dst.writableBytes
      • getBytes

        public abstract ByteBuf getBytes​(int index,
                                         ByteBuf dst,
                                         int dstIndex,
                                         int length)
        Transfers this buffer's data to the specified destination starting at the specified absolute index. This method does not modify readerIndex or writerIndex of both the source (i.e. this) and the destination.
        Parameters:
        dstIndex - the first index of the destination
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0, if the specified dstIndex is less than 0, if index + length is greater than this.capacity, or if dstIndex + length is greater than dst.capacity
      • getBytes

        public abstract ByteBuf getBytes​(int index,
                                         byte[] dst)
        Transfers this buffer's data to the specified destination starting at the specified absolute index. This method does not modify readerIndex or writerIndex of this buffer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or if index + dst.length is greater than this.capacity
      • getBytes

        public abstract ByteBuf getBytes​(int index,
                                         byte[] dst,
                                         int dstIndex,
                                         int length)
        Transfers this buffer's data to the specified destination starting at the specified absolute index. This method does not modify readerIndex or writerIndex of this buffer.
        Parameters:
        dstIndex - the first index of the destination
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0, if the specified dstIndex is less than 0, if index + length is greater than this.capacity, or if dstIndex + length is greater than dst.length
      • getBytes

        public abstract ByteBuf getBytes​(int index,
                                         java.nio.ByteBuffer dst)
        Transfers this buffer's data to the specified destination starting at the specified absolute index until the destination's position reaches its limit. This method does not modify readerIndex or writerIndex of this buffer while the destination's position will be increased.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or if index + dst.remaining() is greater than this.capacity
      • getBytes

        public abstract ByteBuf getBytes​(int index,
                                         java.io.OutputStream out,
                                         int length)
                                  throws java.io.IOException
        Transfers this buffer's data to the specified stream starting at the specified absolute index. This method does not modify readerIndex or writerIndex of this buffer.
        Parameters:
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or if index + length is greater than this.capacity
        java.io.IOException - if the specified stream threw an exception during I/O
      • setBoolean

        public abstract ByteBuf setBoolean​(int index,
                                           boolean value)
        Sets the specified boolean at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 1 is greater than this.capacity
      • setByte

        public abstract ByteBuf setByte​(int index,
                                        int value)
        Sets the specified byte at the specified absolute index in this buffer. The 24 high-order bits of the specified value are ignored. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 1 is greater than this.capacity
      • setShort

        public abstract ByteBuf setShort​(int index,
                                         int value)
        Sets the specified 16-bit short integer at the specified absolute index in this buffer. The 16 high-order bits of the specified value are ignored. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 2 is greater than this.capacity
      • setMedium

        public abstract ByteBuf setMedium​(int index,
                                          int value)
        Sets the specified 24-bit medium integer at the specified absolute index in this buffer. Please note that the most significant byte is ignored in the specified value. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 3 is greater than this.capacity
      • setInt

        public abstract ByteBuf setInt​(int index,
                                       int value)
        Sets the specified 32-bit integer at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 4 is greater than this.capacity
      • setLong

        public abstract ByteBuf setLong​(int index,
                                        long value)
        Sets the specified 64-bit long integer at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 8 is greater than this.capacity
      • setChar

        public abstract ByteBuf setChar​(int index,
                                        int value)
        Sets the specified 2-byte UTF-16 character at the specified absolute index in this buffer. The 16 high-order bits of the specified value are ignored. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 2 is greater than this.capacity
      • setFloat

        public abstract ByteBuf setFloat​(int index,
                                         float value)
        Sets the specified 32-bit floating-point number at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 4 is greater than this.capacity
      • setDouble

        public abstract ByteBuf setDouble​(int index,
                                          double value)
        Sets the specified 64-bit floating-point number at the specified absolute index in this buffer. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or index + 8 is greater than this.capacity
      • setBytes

        public abstract ByteBuf setBytes​(int index,
                                         ByteBuf src)
        Transfers the specified source buffer's data to this buffer starting at the specified absolute index until the source buffer becomes unreadable. This method is basically same with setBytes(int, ByteBuf, int, int), except that this method increases the readerIndex of the source buffer by the number of the transferred bytes while setBytes(int, ByteBuf, int, int) does not. This method does not modify readerIndex or writerIndex of the source buffer (i.e. this).
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or if index + src.readableBytes is greater than this.capacity
      • setBytes

        public abstract ByteBuf setBytes​(int index,
                                         ByteBuf src,
                                         int length)
        Transfers the specified source buffer's data to this buffer starting at the specified absolute index. This method is basically same with setBytes(int, ByteBuf, int, int), except that this method increases the readerIndex of the source buffer by the number of the transferred bytes while setBytes(int, ByteBuf, int, int) does not. This method does not modify readerIndex or writerIndex of the source buffer (i.e. this).
        Parameters:
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0, if index + length is greater than this.capacity, or if length is greater than src.readableBytes
      • setBytes

        public abstract ByteBuf setBytes​(int index,
                                         ByteBuf src,
                                         int srcIndex,
                                         int length)
        Transfers the specified source buffer's data to this buffer starting at the specified absolute index. This method does not modify readerIndex or writerIndex of both the source (i.e. this) and the destination.
        Parameters:
        srcIndex - the first index of the source
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0, if the specified srcIndex is less than 0, if index + length is greater than this.capacity, or if srcIndex + length is greater than src.capacity
      • setBytes

        public abstract ByteBuf setBytes​(int index,
                                         byte[] src)
        Transfers the specified source array's data to this buffer starting at the specified absolute index. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or if index + src.length is greater than this.capacity
      • setBytes

        public abstract ByteBuf setBytes​(int index,
                                         byte[] src,
                                         int srcIndex,
                                         int length)
        Transfers the specified source array's data to this buffer starting at the specified absolute index. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0, if the specified srcIndex is less than 0, if index + length is greater than this.capacity, or if srcIndex + length is greater than src.length
      • setBytes

        public abstract ByteBuf setBytes​(int index,
                                         java.nio.ByteBuffer src)
        Transfers the specified source buffer's data to this buffer starting at the specified absolute index until the source buffer's position reaches its limit. This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or if index + src.remaining() is greater than this.capacity
      • setBytes

        public abstract int setBytes​(int index,
                                     java.io.InputStream in,
                                     int length)
                              throws java.io.IOException
        Transfers the content of the specified source stream to this buffer starting at the specified absolute index. This method does not modify readerIndex or writerIndex of this buffer.
        Parameters:
        length - the number of bytes to transfer
        Returns:
        the actual number of bytes read in from the specified channel. -1 if the specified channel is closed.
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or if index + length is greater than this.capacity
        java.io.IOException - if the specified stream threw an exception during I/O
      • setZero

        public abstract ByteBuf setZero​(int index,
                                        int length)
        Fills this buffer with NUL (0x00) starting at the specified absolute index. This method does not modify readerIndex or writerIndex of this buffer.
        Parameters:
        length - the number of NULs to write to the buffer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified index is less than 0 or if index + length is greater than this.capacity
      • readBoolean

        public abstract boolean readBoolean()
        Gets a boolean at the current readerIndex and increases the readerIndex by 1 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 1
      • readByte

        public abstract byte readByte()
        Gets a byte at the current readerIndex and increases the readerIndex by 1 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 1
      • readUnsignedByte

        public abstract short readUnsignedByte()
        Gets an unsigned byte at the current readerIndex and increases the readerIndex by 1 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 1
      • readShort

        public abstract short readShort()
        Gets a 16-bit short integer at the current readerIndex and increases the readerIndex by 2 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 2
      • readUnsignedShort

        public abstract int readUnsignedShort()
        Gets an unsigned 16-bit short integer at the current readerIndex and increases the readerIndex by 2 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 2
      • readMedium

        public abstract int readMedium()
        Gets a 24-bit medium integer at the current readerIndex and increases the readerIndex by 3 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 3
      • readUnsignedMedium

        public abstract int readUnsignedMedium()
        Gets an unsigned 24-bit medium integer at the current readerIndex and increases the readerIndex by 3 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 3
      • readInt

        public abstract int readInt()
        Gets a 32-bit integer at the current readerIndex and increases the readerIndex by 4 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 4
      • readUnsignedInt

        public abstract long readUnsignedInt()
        Gets an unsigned 32-bit integer at the current readerIndex and increases the readerIndex by 4 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 4
      • readLong

        public abstract long readLong()
        Gets a 64-bit integer at the current readerIndex and increases the readerIndex by 8 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 8
      • readChar

        public abstract char readChar()
        Gets a 2-byte UTF-16 character at the current readerIndex and increases the readerIndex by 2 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 2
      • readFloat

        public abstract float readFloat()
        Gets a 32-bit floating point number at the current readerIndex and increases the readerIndex by 4 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 4
      • readDouble

        public abstract double readDouble()
        Gets a 64-bit floating point number at the current readerIndex and increases the readerIndex by 8 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.readableBytes is less than 8
      • readBytes

        public abstract ByteBuf readBytes​(int length)
        Transfers this buffer's data to a newly created buffer starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length). The returned buffer's readerIndex and writerIndex are 0 and length respectively.
        Parameters:
        length - the number of bytes to transfer
        Returns:
        the newly created buffer which contains the transferred bytes
        Throws:
        java.lang.IndexOutOfBoundsException - if length is greater than this.readableBytes
      • readSlice

        public abstract ByteBuf readSlice​(int length)
        Returns a new slice of this buffer's sub-region starting at the current readerIndex and increases the readerIndex by the size of the new slice (= length).

        Also be aware that this method will NOT call #retain() and so the reference count will NOT be increased.

        Parameters:
        length - the size of the new slice
        Returns:
        the newly created slice
        Throws:
        java.lang.IndexOutOfBoundsException - if length is greater than this.readableBytes
      • readBytes

        public abstract ByteBuf readBytes​(ByteBuf dst)
        Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination becomes non-writable, and increases the readerIndex by the number of the transferred bytes. This method is basically same with readBytes(ByteBuf, int, int), except that this method increases the writerIndex of the destination by the number of the transferred bytes while readBytes(ByteBuf, int, int) does not.
        Throws:
        java.lang.IndexOutOfBoundsException - if dst.writableBytes is greater than this.readableBytes
      • readBytes

        public abstract ByteBuf readBytes​(ByteBuf dst,
                                          int length)
        Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length). This method is basically same with readBytes(ByteBuf, int, int), except that this method increases the writerIndex of the destination by the number of the transferred bytes (= length) while readBytes(ByteBuf, int, int) does not.
        Throws:
        java.lang.IndexOutOfBoundsException - if length is greater than this.readableBytes or if length is greater than dst.writableBytes
      • readBytes

        public abstract ByteBuf readBytes​(ByteBuf dst,
                                          int dstIndex,
                                          int length)
        Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
        Parameters:
        dstIndex - the first index of the destination
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified dstIndex is less than 0, if length is greater than this.readableBytes, or if dstIndex + length is greater than dst.capacity
      • readBytes

        public abstract ByteBuf readBytes​(byte[] dst)
        Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= dst.length).
        Throws:
        java.lang.IndexOutOfBoundsException - if dst.length is greater than this.readableBytes
      • readBytes

        public abstract ByteBuf readBytes​(byte[] dst,
                                          int dstIndex,
                                          int length)
        Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
        Parameters:
        dstIndex - the first index of the destination
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified dstIndex is less than 0, if length is greater than this.readableBytes, or if dstIndex + length is greater than dst.length
      • readBytes

        public abstract ByteBuf readBytes​(java.nio.ByteBuffer dst)
        Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination's position reaches its limit, and increases the readerIndex by the number of the transferred bytes.
        Throws:
        java.lang.IndexOutOfBoundsException - if dst.remaining() is greater than this.readableBytes
      • readBytes

        public abstract ByteBuf readBytes​(java.io.OutputStream out,
                                          int length)
                                   throws java.io.IOException
        Transfers this buffer's data to the specified stream starting at the current readerIndex.
        Parameters:
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if length is greater than this.readableBytes
        java.io.IOException - if the specified stream threw an exception during I/O
      • skipBytes

        public abstract ByteBuf skipBytes​(int length)
        Increases the current readerIndex by the specified length in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if length is greater than this.readableBytes
      • writeBoolean

        public abstract ByteBuf writeBoolean​(boolean value)
        Sets the specified boolean at the current writerIndex and increases the writerIndex by 1 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.writableBytes is less than 1
      • writeByte

        public abstract ByteBuf writeByte​(int value)
        Sets the specified byte at the current writerIndex and increases the writerIndex by 1 in this buffer. The 24 high-order bits of the specified value are ignored.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.writableBytes is less than 1
      • writeShort

        public abstract ByteBuf writeShort​(int value)
        Sets the specified 16-bit short integer at the current writerIndex and increases the writerIndex by 2 in this buffer. The 16 high-order bits of the specified value are ignored.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.writableBytes is less than 2
      • writeMedium

        public abstract ByteBuf writeMedium​(int value)
        Sets the specified 24-bit medium integer at the current writerIndex and increases the writerIndex by 3 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.writableBytes is less than 3
      • writeInt

        public abstract ByteBuf writeInt​(int value)
        Sets the specified 32-bit integer at the current writerIndex and increases the writerIndex by 4 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.writableBytes is less than 4
      • writeLong

        public abstract ByteBuf writeLong​(long value)
        Sets the specified 64-bit long integer at the current writerIndex and increases the writerIndex by 8 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.writableBytes is less than 8
      • writeChar

        public abstract ByteBuf writeChar​(int value)
        Sets the specified 2-byte UTF-16 character at the current writerIndex and increases the writerIndex by 2 in this buffer. The 16 high-order bits of the specified value are ignored.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.writableBytes is less than 2
      • writeFloat

        public abstract ByteBuf writeFloat​(float value)
        Sets the specified 32-bit floating point number at the current writerIndex and increases the writerIndex by 4 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.writableBytes is less than 4
      • writeDouble

        public abstract ByteBuf writeDouble​(double value)
        Sets the specified 64-bit floating point number at the current writerIndex and increases the writerIndex by 8 in this buffer.
        Throws:
        java.lang.IndexOutOfBoundsException - if this.writableBytes is less than 8
      • writeBytes

        public abstract ByteBuf writeBytes​(ByteBuf src)
        Transfers the specified source buffer's data to this buffer starting at the current writerIndex until the source buffer becomes unreadable, and increases the writerIndex by the number of the transferred bytes. This method is basically same with writeBytes(ByteBuf, int, int), except that this method increases the readerIndex of the source buffer by the number of the transferred bytes while writeBytes(ByteBuf, int, int) does not.
        Throws:
        java.lang.IndexOutOfBoundsException - if src.readableBytes is greater than this.writableBytes
      • writeBytes

        public abstract ByteBuf writeBytes​(ByteBuf src,
                                           int length)
        Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length). This method is basically same with writeBytes(ByteBuf, int, int), except that this method increases the readerIndex of the source buffer by the number of the transferred bytes (= length) while writeBytes(ByteBuf, int, int) does not.
        Parameters:
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if length is greater than this.writableBytes or if length is greater then src.readableBytes
      • writeBytes

        public abstract ByteBuf writeBytes​(ByteBuf src,
                                           int srcIndex,
                                           int length)
        Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).
        Parameters:
        srcIndex - the first index of the source
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified srcIndex is less than 0, if srcIndex + length is greater than src.capacity, or if length is greater than this.writableBytes
      • writeBytes

        public abstract ByteBuf writeBytes​(byte[] src)
        Transfers the specified source array's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= src.length).
        Throws:
        java.lang.IndexOutOfBoundsException - if src.length is greater than this.writableBytes
      • writeBytes

        public abstract ByteBuf writeBytes​(byte[] src,
                                           int srcIndex,
                                           int length)
        Transfers the specified source array's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).
        Parameters:
        srcIndex - the first index of the source
        length - the number of bytes to transfer
        Throws:
        java.lang.IndexOutOfBoundsException - if the specified srcIndex is less than 0, if srcIndex + length is greater than src.length, or if length is greater than this.writableBytes
      • writeBytes

        public abstract ByteBuf writeBytes​(java.nio.ByteBuffer src)
        Transfers the specified source buffer's data to this buffer starting at the current writerIndex until the source buffer's position reaches its limit, and increases the writerIndex by the number of the transferred bytes.
        Throws:
        java.lang.IndexOutOfBoundsException - if src.remaining() is greater than this.writableBytes
      • writeBytes

        public abstract int writeBytes​(java.io.InputStream in,
                                       int length)
                                throws java.io.IOException
        Transfers the content of the specified stream to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes.
        Parameters:
        length - the number of bytes to transfer
        Returns:
        the actual number of bytes read in from the specified stream
        Throws:
        java.lang.IndexOutOfBoundsException - if length is greater than this.writableBytes
        java.io.IOException - if the specified stream threw an exception during I/O
      • writeZero

        public abstract ByteBuf writeZero​(int length)
        Fills this buffer with NUL (0x00) starting at the current writerIndex and increases the writerIndex by the specified length.
        Parameters:
        length - the number of NULs to write to the buffer
        Throws:
        java.lang.IndexOutOfBoundsException - if length is greater than this.writableBytes
      • indexOf

        public abstract int indexOf​(int fromIndex,
                                    int toIndex,
                                    byte value)
        Locates the first occurrence of the specified value in this buffer. The search takes place from the specified fromIndex (inclusive) to the specified toIndex (exclusive).

        If fromIndex is greater than toIndex, the search is performed in a reversed order.

        This method does not modify readerIndex or writerIndex of this buffer.

        Returns:
        the absolute index of the first occurrence if found. -1 otherwise.
      • bytesBefore

        public abstract int bytesBefore​(byte value)
        Locates the first occurrence of the specified value in this buffer. The search takes place from the current readerIndex (inclusive) to the current writerIndex (exclusive).

        This method does not modify readerIndex or writerIndex of this buffer.

        Returns:
        the number of bytes between the current readerIndex and the first occurrence if found. -1 otherwise.
      • bytesBefore

        public abstract int bytesBefore​(int length,
                                        byte value)
        Locates the first occurrence of the specified value in this buffer. The search starts from the current readerIndex (inclusive) and lasts for the specified length.

        This method does not modify readerIndex or writerIndex of this buffer.

        Returns:
        the number of bytes between the current readerIndex and the first occurrence if found. -1 otherwise.
        Throws:
        java.lang.IndexOutOfBoundsException - if length is greater than this.readableBytes
      • bytesBefore

        public abstract int bytesBefore​(int index,
                                        int length,
                                        byte value)
        Locates the first occurrence of the specified value in this buffer. The search starts from the specified index (inclusive) and lasts for the specified length.

        This method does not modify readerIndex or writerIndex of this buffer.

        Returns:
        the number of bytes between the specified index and the first occurrence if found. -1 otherwise.
        Throws:
        java.lang.IndexOutOfBoundsException - if index + length is greater than this.capacity
      • copy

        public abstract ByteBuf copy()
        Returns a copy of this buffer's readable bytes. Modifying the content of the returned buffer or this buffer does not affect each other at all. This method is identical to buf.copy(buf.readerIndex(), buf.readableBytes()). This method does not modify readerIndex or writerIndex of this buffer.
      • copy

        public abstract ByteBuf copy​(int index,
                                     int length)
        Returns a copy of this buffer's sub-region. Modifying the content of the returned buffer or this buffer does not affect each other at all. This method does not modify readerIndex or writerIndex of this buffer.
      • slice

        public abstract ByteBuf slice()
        Returns a slice of this buffer's readable bytes. Modifying the content of the returned buffer or this buffer affects each other's content while they maintain separate indexes and marks. This method is identical to buf.slice(buf.readerIndex(), buf.readableBytes()). This method does not modify readerIndex or writerIndex of this buffer.

        Also be aware that this method will NOT call #retain() and so the reference count will NOT be increased.

      • slice

        public abstract ByteBuf slice​(int index,
                                      int length)
        Returns a slice of this buffer's sub-region. Modifying the content of the returned buffer or this buffer affects each other's content while they maintain separate indexes and marks. This method does not modify readerIndex or writerIndex of this buffer.

        Also be aware that this method will NOT call #retain() and so the reference count will NOT be increased.

      • duplicate

        public abstract ByteBuf duplicate()
        Returns a buffer which shares the whole region of this buffer. Modifying the content of the returned buffer or this buffer affects each other's content while they maintain separate indexes and marks. This method does not modify readerIndex or writerIndex of this buffer.

        The reader and writer marks will not be duplicated. Also be aware that this method will NOT call #retain() and so the reference count will NOT be increased.

        Returns:
        A buffer whose readable content is equivalent to the buffer returned by slice(). However this buffer will share the capacity of the underlying buffer, and therefore allows access to all of the underlying content if necessary.
      • nioBufferCount

        public abstract int nioBufferCount()
        Returns the maximum number of NIO ByteBuffers that consist this buffer. Note that nioBuffers() or nioBuffers(int, int) might return a less number of ByteBuffers.
        Returns:
        -1 if this buffer has no underlying ByteBuffer. the number of the underlying ByteBuffers if this buffer has at least one underlying ByteBuffer. Note that this method does not return 0 to avoid confusion.
        See Also:
        nioBuffer(), nioBuffer(int, int), nioBuffers(), nioBuffers(int, int)
      • nioBuffer

        public abstract java.nio.ByteBuffer nioBuffer()
        Exposes this buffer's readable bytes as an NIO ByteBuffer. The returned buffer either share or contains the copied content of this buffer, while changing the position and limit of the returned NIO buffer does not affect the indexes and marks of this buffer. This method is identical to buf.nioBuffer(buf.readerIndex(), buf.readableBytes()). This method does not modify readerIndex or writerIndex of this buffer. Please note that the returned NIO buffer will not see the changes of this buffer if this buffer is a dynamic buffer and it adjusted its capacity.
        Throws:
        java.lang.UnsupportedOperationException - if this buffer cannot create a ByteBuffer that shares the content with itself
        See Also:
        nioBufferCount(), nioBuffers(), nioBuffers(int, int)
      • nioBuffer

        public abstract java.nio.ByteBuffer nioBuffer​(int index,
                                                      int length)
        Exposes this buffer's sub-region as an NIO ByteBuffer. The returned buffer either share or contains the copied content of this buffer, while changing the position and limit of the returned NIO buffer does not affect the indexes and marks of this buffer. This method does not modify readerIndex or writerIndex of this buffer. Please note that the returned NIO buffer will not see the changes of this buffer if this buffer is a dynamic buffer and it adjusted its capacity.
        Throws:
        java.lang.UnsupportedOperationException - if this buffer cannot create a ByteBuffer that shares the content with itself
        See Also:
        nioBufferCount(), nioBuffers(), nioBuffers(int, int)
      • internalNioBuffer

        public abstract java.nio.ByteBuffer internalNioBuffer​(int index,
                                                              int length)
        Internal use only: Exposes the internal NIO buffer.
      • nioBuffers

        public abstract java.nio.ByteBuffer[] nioBuffers()
        Exposes this buffer's readable bytes as an NIO ByteBuffer's. The returned buffer either share or contains the copied content of this buffer, while changing the position and limit of the returned NIO buffer does not affect the indexes and marks of this buffer. This method does not modify readerIndex or writerIndex of this buffer. Please note that the returned NIO buffer will not see the changes of this buffer if this buffer is a dynamic buffer and it adjusted its capacity.
        Throws:
        java.lang.UnsupportedOperationException - if this buffer cannot create a ByteBuffer that shares the content with itself
        See Also:
        nioBufferCount(), nioBuffer(), nioBuffer(int, int)
      • nioBuffers

        public abstract java.nio.ByteBuffer[] nioBuffers​(int index,
                                                         int length)
        Exposes this buffer's bytes as an NIO ByteBuffer's for the specified index and length The returned buffer either share or contains the copied content of this buffer, while changing the position and limit of the returned NIO buffer does not affect the indexes and marks of this buffer. This method does not modify readerIndex or writerIndex of this buffer. Please note that the returned NIO buffer will not see the changes of this buffer if this buffer is a dynamic buffer and it adjusted its capacity.
        Throws:
        java.lang.UnsupportedOperationException - if this buffer cannot create a ByteBuffer that shares the content with itself
        See Also:
        nioBufferCount(), nioBuffer(), nioBuffer(int, int)
      • hasArray

        public abstract boolean hasArray()
        Returns true if and only if this buffer has a backing byte array. If this method returns true, you can safely call array() and arrayOffset().
      • array

        public abstract byte[] array()
        Returns the backing byte array of this buffer.
        Throws:
        java.lang.UnsupportedOperationException - if there no accessible backing byte array
      • arrayOffset

        public abstract int arrayOffset()
        Returns the offset of the first byte within the backing byte array of this buffer.
        Throws:
        java.lang.UnsupportedOperationException - if there no accessible backing byte array
      • hasMemoryAddress

        public abstract boolean hasMemoryAddress()
        Returns true if and only if this buffer has a reference to the low-level memory address that points to the backing data.
      • memoryAddress

        public abstract long memoryAddress()
        Returns the low-level memory address that point to the first byte of ths backing data.
        Throws:
        java.lang.UnsupportedOperationException - if this buffer does not support accessing the low-level memory address
      • toString

        public abstract java.lang.String toString​(java.nio.charset.Charset charset)
        Decodes this buffer's readable bytes into a string with the specified character set name. This method is identical to buf.toString(buf.readerIndex(), buf.readableBytes(), charsetName). This method does not modify readerIndex or writerIndex of this buffer.
        Throws:
        java.nio.charset.UnsupportedCharsetException - if the specified character set name is not supported by the current VM
      • toString

        public abstract java.lang.String toString​(int index,
                                                  int length,
                                                  java.nio.charset.Charset charset)
        Decodes this buffer's sub-region into a string with the specified character set. This method does not modify readerIndex or writerIndex of this buffer.
      • hashCode

        public abstract int hashCode()
        Returns a hash code which was calculated from the content of this buffer. If there's a byte array which is equal to this array, both arrays should return the same value.
        Overrides:
        hashCode in class java.lang.Object
      • equals

        public abstract boolean equals​(java.lang.Object obj)
        Determines if the content of the specified buffer is identical to the content of this array. 'Identical' here means:
        • the size of the contents of the two buffers are same and
        • every single byte of the content of the two buffers are same.
        Please note that it does not compare readerIndex() nor writerIndex(). This method also returns false for null and an object which is not an instance of ByteBuf type.
        Overrides:
        equals in class java.lang.Object
      • compareTo

        public abstract int compareTo​(ByteBuf buffer)
        Compares the content of the specified buffer to the content of this buffer. Comparison is performed in the same manner with the string comparison functions of various languages such as strcmp, memcmp and String.compareTo(String).
        Specified by:
        compareTo in interface java.lang.Comparable<ByteBuf>
      • toString

        public abstract java.lang.String toString()
        Returns the string representation of this buffer. This method does not necessarily return the whole content of the buffer but returns the values of the key properties such as readerIndex(), writerIndex() and capacity().
        Overrides:
        toString in class java.lang.Object