com.google.common.collect

Interface SortedMultiset<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

Author:

Louis Wasserman

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.common.collect.Multiset

Multiset.Entry<E>

Method Summary

Methods

Modifier and Type	Method and Description
Comparator<? super E>	comparator() Returns the comparator that orders this multiset, or Ordering.natural() if the natural ordering of the elements is used.
SortedMultiset<E>	descendingMultiset() Returns a descending view of this multiset.
NavigableSet<E>	elementSet() Returns a NavigableSet view of the distinct elements in this multiset.
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.
Multiset.Entry<E>	firstEntry() Returns the entry of the first element in this multiset, or null if this multiset is empty.
SortedMultiset<E>	headMultiset(E upperBound, BoundType boundType) Returns a view of this multiset restricted to the elements less than upperBound, optionally including upperBound itself.
Iterator<E>	iterator() Returns an iterator over the elements in this collection.
Multiset.Entry<E>	lastEntry() Returns the entry of the last element in this multiset, or null if this multiset is empty.
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.
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.
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.
SortedMultiset<E>	tailMultiset(E lowerBound, BoundType boundType) Returns a view of this multiset restricted to the elements greater than lowerBound, optionally including lowerBound itself.

Methods inherited from interface com.google.common.collect.Multiset

add, add, contains, containsAll, count, equals, hashCode, remove, remove, removeAll, retainAll, setCount, setCount, toString

Methods inherited from interface java.util.Collection

addAll, clear, isEmpty, size, toArray, toArray

Method Detail

comparator

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

NavigableSet<E> elementSet()

Returns a NavigableSet view of the distinct elements in this multiset.

Returns:

a view of the set of distinct elements in this multiset

Since:

14.0 (present with return type SortedSet since 11.0)

entrySet

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.

Returns:

a set of entries representing the data of this multiset

iterator

Iterator<E> iterator()

Returns an iterator over the elements in this collection. There are no guarantees concerning the order in which the elements are returned (unless this collection is an instance of some class that provides a guarantee).

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.

Returns:

an Iterator over the elements in this collection

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.