001/* 002 * Copyright (C) 2007 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package com.google.common.collect; 018 019import com.google.common.annotations.GwtCompatible; 020import com.google.errorprone.annotations.CanIgnoreReturnValue; 021import java.util.Collection; 022import java.util.Comparator; 023import java.util.Map; 024import java.util.Set; 025import java.util.SortedMap; 026import java.util.SortedSet; 027import javax.annotation.CheckForNull; 028import org.checkerframework.checker.nullness.qual.Nullable; 029 030/** 031 * A {@code SetMultimap} whose set of values for a given key are kept sorted; that is, they comprise 032 * a {@link SortedSet}. It cannot hold duplicate key-value pairs; adding a key-value pair that's 033 * already in the multimap has no effect. This interface does not specify the ordering of the 034 * multimap's keys. See the {@link Multimap} documentation for information common to all multimaps. 035 * 036 * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods each return a {@link 037 * SortedSet} of values, while {@link Multimap#entries()} returns a {@link Set} of map entries. 038 * Though the method signature doesn't say so explicitly, the map returned by {@link #asMap} has 039 * {@code SortedSet} values. 040 * 041 * <p><b>Warning:</b> As in all {@link SetMultimap}s, do not modify either a key <i>or a value</i> 042 * of a {@code SortedSetMultimap} in a way that affects its {@link Object#equals} behavior (or its 043 * position in the order of the values). Undefined behavior and bugs will result. 044 * 045 * <p>See the Guava User Guide article on <a href= 046 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap">{@code Multimap}</a>. 047 * 048 * @author Jared Levy 049 * @since 2.0 050 */ 051@GwtCompatible 052@ElementTypesAreNonnullByDefault 053public interface SortedSetMultimap<K extends @Nullable Object, V extends @Nullable Object> 054 extends SetMultimap<K, V> { 055 // Following Javadoc copied from Multimap. 056 057 /** 058 * Returns a collection view of all values associated with a key. If no mappings in the multimap 059 * have the provided key, an empty collection is returned. 060 * 061 * <p>Changes to the returned collection will update the underlying multimap, and vice versa. 062 * 063 * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method 064 * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the 065 * {@link Multimap} interface. 066 */ 067 @Override 068 SortedSet<V> get(@ParametricNullness K key); 069 070 /** 071 * Removes all values associated with a given key. 072 * 073 * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method 074 * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the 075 * {@link Multimap} interface. 076 */ 077 @CanIgnoreReturnValue 078 @Override 079 SortedSet<V> removeAll(@CheckForNull Object key); 080 081 /** 082 * Stores a collection of values with the same key, replacing any existing values for that key. 083 * 084 * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method 085 * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the 086 * {@link Multimap} interface. 087 * 088 * <p>Any duplicates in {@code values} will be stored in the multimap once. 089 */ 090 @CanIgnoreReturnValue 091 @Override 092 SortedSet<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values); 093 094 /** 095 * Returns a map view that associates each key with the corresponding values in the multimap. 096 * Changes to the returned map, such as element removal, will update the underlying multimap. The 097 * map does not support {@code setValue()} on its entries, {@code put}, or {@code putAll}. 098 * 099 * <p>When passed a key that is present in the map, {@code asMap().get(Object)} has the same 100 * behavior as {@link #get}, returning a live collection. When passed a key that is not present, 101 * however, {@code asMap().get(Object)} returns {@code null} instead of an empty collection. 102 * 103 * <p><b>Note:</b> The returned map's values are guaranteed to be of type {@link SortedSet}. To 104 * obtain this map with the more specific generic type {@code Map<K, SortedSet<V>>}, call {@link 105 * Multimaps#asMap(SortedSetMultimap)} instead. <b>However</b>, the returned map <i>itself</i> is 106 * not necessarily a {@link SortedMap}: A {@code SortedSetMultimap} must expose the <i>values</i> 107 * for a given key in sorted order, but it need not expose the <i>keys</i> in sorted order. 108 * Individual {@code SortedSetMultimap} implementations, like those built with {@link 109 * MultimapBuilder#treeKeys()}, may make additional guarantees. 110 */ 111 @Override 112 Map<K, Collection<V>> asMap(); 113 114 /** 115 * Returns the comparator that orders the multimap values, with {@code null} indicating that 116 * natural ordering is used. 117 */ 118 @CheckForNull 119 Comparator<? super V> valueComparator(); 120}