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.List; 023import java.util.Map; 024import javax.annotation.CheckForNull; 025import org.checkerframework.checker.nullness.qual.Nullable; 026 027/** 028 * A {@code Multimap} that can hold duplicate key-value pairs and that maintains the insertion 029 * ordering of values for a given key. See the {@link Multimap} documentation for information common 030 * to all multimaps. 031 * 032 * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods each return a {@link 033 * List} of values. Though the method signature doesn't say so explicitly, the map returned by 034 * {@link #asMap} has {@code List} values. 035 * 036 * <p>See the Guava User Guide article on <a href= 037 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap">{@code Multimap}</a>. 038 * 039 * @author Jared Levy 040 * @since 2.0 041 */ 042@GwtCompatible 043@ElementTypesAreNonnullByDefault 044public interface ListMultimap<K extends @Nullable Object, V extends @Nullable Object> 045 extends Multimap<K, V> { 046 /** 047 * {@inheritDoc} 048 * 049 * <p>Because the values for a given key may have duplicates and follow the insertion ordering, 050 * this method returns a {@link List}, instead of the {@link java.util.Collection} specified in 051 * the {@link Multimap} interface. 052 */ 053 @Override 054 List<V> get(@ParametricNullness K key); 055 056 /** 057 * {@inheritDoc} 058 * 059 * <p>Because the values for a given key may have duplicates and follow the insertion ordering, 060 * this method returns a {@link List}, instead of the {@link java.util.Collection} specified in 061 * the {@link Multimap} interface. 062 */ 063 @CanIgnoreReturnValue 064 @Override 065 List<V> removeAll(@CheckForNull Object key); 066 067 /** 068 * {@inheritDoc} 069 * 070 * <p>Because the values for a given key may have duplicates and follow the insertion ordering, 071 * this method returns a {@link List}, instead of the {@link java.util.Collection} specified in 072 * the {@link Multimap} interface. 073 */ 074 @CanIgnoreReturnValue 075 @Override 076 List<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values); 077 078 /** 079 * {@inheritDoc} 080 * 081 * <p><b>Note:</b> The returned map's values are guaranteed to be of type {@link List}. To obtain 082 * this map with the more specific generic type {@code Map<K, List<V>>}, call {@link 083 * Multimaps#asMap(ListMultimap)} instead. 084 */ 085 @Override 086 Map<K, Collection<V>> asMap(); 087 088 /** 089 * Compares the specified object to this multimap for equality. 090 * 091 * <p>Two {@code ListMultimap} instances are equal if, for each key, they contain the same values 092 * in the same order. If the value orderings disagree, the multimaps will not be considered equal. 093 * 094 * <p>An empty {@code ListMultimap} is equal to any other empty {@code Multimap}, including an 095 * empty {@code SetMultimap}. 096 */ 097 @Override 098 boolean equals(@CheckForNull Object obj); 099}