Package com.google.common.collect

Interface SortedMultiset<E>

  • All Superinterfaces:
    java.util.Collection<E>, java.lang.Iterable<E>, Multiset<E>
    All Known Implementing Classes:
    ForwardingSortedMultiset, ForwardingSortedMultiset.StandardDescendingMultiset, ImmutableSortedMultiset, TreeMultiset
    @Beta
@GwtCompatible(emulated=true)
public interface SortedMultiset<E>
    A Multiset which maintains the ordering of its elements, according to either their natural order or an explicit Comparator. This order is reflected when iterating over the sorted multiset, either directly, or through its elementSet or entrySet views. In all cases, this implementation uses Comparable.compareTo(T) or Comparator.compare(T, T) instead of Object.equals(java.lang.Object) to determine equivalence of instances.

    Warning: The comparison must be consistent with equals as explained by the Comparable class specification. Otherwise, the resulting multiset will violate the Collection contract, which it is specified in terms of Object.equals(java.lang.Object).

    See the Guava User Guide article on Multiset.

    Since:
    11.0

    • Method Detail

      • comparator

        java.util.Comparator<? super E> comparator()
        Returns the comparator that orders this multiset, or Ordering.natural() if the natural ordering of the elements is used.

      • firstEntry

        Multiset.Entry<E> firstEntry()
        Returns the entry of the first element in this multiset, or null if this multiset is empty.

      • lastEntry

        Multiset.Entry<E> lastEntry()
        Returns the entry of the last element in this multiset, or null if this multiset is empty.

      • pollFirstEntry

        Multiset.Entry<E> pollFirstEntry()
        Returns and removes the entry associated with the lowest element in this multiset, or returns null if this multiset is empty.

      • pollLastEntry

        Multiset.Entry<E> pollLastEntry()
        Returns and removes the entry associated with the greatest element in this multiset, or returns null if this multiset is empty.

      • elementSet

        java.util.NavigableSet<E> elementSet()
        Returns a NavigableSet view of the distinct elements in this multiset.
        Specified by:
        elementSet in interface Multiset<E>
        Returns:
        a view of the set of distinct elements in this multiset
        Since:
        14.0 (present with return type SortedSet since 11.0)

      • entrySet

        java.util.Set<Multiset.Entry<E>> entrySet()
        Returns a view of the contents of this multiset, grouped into Multiset.Entry instances, each providing an element of the multiset and the count of that element. This set contains exactly one entry for each distinct element in the multiset (thus it always has the same size as the Multiset.elementSet()). The order of the elements in the element set is unspecified.

        The entry set is backed by the same data as the multiset, so any change to either is immediately reflected in the other. However, multiset changes may or may not be reflected in any Entry instances already retrieved from the entry set (this is implementation-dependent). Furthermore, implementations are not required to support modifications to the entry set at all, and the Entry instances themselves don't even have methods for modification. See the specific implementation class for more details on how its entry set handles modifications.

        The entrySet's iterator returns entries in ascending element order according to the this multiset's comparator.

        Specified by:
        entrySet in interface Multiset<E>
        Returns:
        a set of entries representing the data of this multiset

      • iterator

        java.util.Iterator<E> iterator()

        Elements that occur multiple times in the multiset will appear multiple times in this iterator, though not necessarily sequentially.

        The iterator returns the elements in ascending order according to this multiset's comparator.

        Specified by:
        iterator in interface java.util.Collection<E>
        Specified by:
        iterator in interface java.lang.Iterable<E>
        Specified by:
        iterator in interface Multiset<E>

      • descendingMultiset

        SortedMultiset<E> descendingMultiset()
        Returns a descending view of this multiset. Modifications made to either map will be reflected in the other.

      • headMultiset

        SortedMultiset<E> headMultiset​(E upperBound,
                               BoundType boundType)
        Returns a view of this multiset restricted to the elements less than upperBound, optionally including upperBound itself. The returned multiset is a view of this multiset, so changes to one will be reflected in the other. The returned multiset supports all operations that this multiset supports.

        The returned multiset will throw an IllegalArgumentException on attempts to add elements outside its range.

      • subMultiset

        SortedMultiset<E> subMultiset​(E lowerBound,
                              BoundType lowerBoundType,
                              E upperBound,
                              BoundType upperBoundType)
        Returns a view of this multiset restricted to the range between lowerBound and upperBound. The returned multiset is a view of this multiset, so changes to one will be reflected in the other. The returned multiset supports all operations that this multiset supports.

        The returned multiset will throw an IllegalArgumentException on attempts to add elements outside its range.

        This method is equivalent to tailMultiset(lowerBound, lowerBoundType).headMultiset(upperBound, upperBoundType).

      • tailMultiset

        SortedMultiset<E> tailMultiset​(E lowerBound,
                               BoundType boundType)
        Returns a view of this multiset restricted to the elements greater than lowerBound, optionally including lowerBound itself. The returned multiset is a view of this multiset, so changes to one will be reflected in the other. The returned multiset supports all operations that this multiset supports.

        The returned multiset will throw an IllegalArgumentException on attempts to add elements outside its range.