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 047 * Multimap}</a>. 048 * 049 * @author Jared Levy 050 * @since 2.0 051 */ 052@GwtCompatible 053@ElementTypesAreNonnullByDefault 054public interface SortedSetMultimap<K extends @Nullable Object, V extends @Nullable Object> 055 extends SetMultimap<K, V> { 056 // Following Javadoc copied from Multimap. 057 058 /** 059 * Returns a collection view of all values associated with a key. If no mappings in the multimap 060 * have the provided key, an empty collection is returned. 061 * 062 * <p>Changes to the returned collection will update the underlying multimap, and vice versa. 063 * 064 * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method 065 * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the 066 * {@link Multimap} interface. 067 */ 068 @Override 069 SortedSet<V> get(@ParametricNullness K key); 070 071 /** 072 * Removes all values associated with a given key. 073 * 074 * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method 075 * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the 076 * {@link Multimap} interface. 077 */ 078 @CanIgnoreReturnValue 079 @Override 080 SortedSet<V> removeAll(@CheckForNull Object key); 081 082 /** 083 * Stores a collection of values with the same key, replacing any existing values for that key. 084 * 085 * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method 086 * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the 087 * {@link Multimap} interface. 088 * 089 * <p>Any duplicates in {@code values} will be stored in the multimap once. 090 */ 091 @CanIgnoreReturnValue 092 @Override 093 SortedSet<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values); 094 095 /** 096 * Returns a map view that associates each key with the corresponding values in the multimap. 097 * Changes to the returned map, such as element removal, will update the underlying multimap. The 098 * map does not support {@code setValue()} on its entries, {@code put}, or {@code putAll}. 099 * 100 * <p>When passed a key that is present in the map, {@code asMap().get(Object)} has the same 101 * behavior as {@link #get}, returning a live collection. When passed a key that is not present, 102 * however, {@code asMap().get(Object)} returns {@code null} instead of an empty collection. 103 * 104 * <p><b>Note:</b> The returned map's values are guaranteed to be of type {@link SortedSet}. To 105 * obtain this map with the more specific generic type {@code Map<K, SortedSet<V>>}, call {@link 106 * Multimaps#asMap(SortedSetMultimap)} instead. <b>However</b>, the returned map <i>itself</i> is 107 * not necessarily a {@link SortedMap}: A {@code SortedSetMultimap} must expose the <i>values</i> 108 * for a given key in sorted order, but it need not expose the <i>keys</i> in sorted order. 109 * Individual {@code SortedSetMultimap} implementations, like those built with {@link 110 * MultimapBuilder#treeKeys()}, may make additional guarantees. 111 */ 112 @Override 113 Map<K, Collection<V>> asMap(); 114 115 /** 116 * Returns the comparator that orders the multimap values, with {@code null} indicating that 117 * natural ordering is used. 118 */ 119 @CheckForNull 120 Comparator<? super V> valueComparator(); 121}