1/*
2 * Copyright (C) 2007 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.collect;
18
19import com.google.common.annotations.GwtCompatible;
20
21import java.util.Collection;
22import java.util.List;
23import java.util.Map;
24
25import javax.annotation.Nullable;
26
27/**
28 * A {@code Multimap} that can hold duplicate key-value pairs and that maintains
29 * the insertion ordering of values for a given key. See the {@link Multimap}
30 * documentation for information common to all multimaps.
31 *
32 * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods
33 * each return a {@link List} of values. Though the method signature doesn't say
34 * so explicitly, the map returned by {@link #asMap} has {@code List} values.
35 *
36 * <p>See the Guava User Guide article on <a href=
37 * "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multimap">
38 * {@code Multimap}</a>.
39 *
40 * @author Jared Levy
41 * @since 2.0 (imported from Google Collections Library)
42 */
43@GwtCompatible
44public interface ListMultimap<K, V> extends Multimap<K, V> {
45  /**
46   * {@inheritDoc}
47   *
48   * <p>Because the values for a given key may have duplicates and follow the
49   * insertion ordering, this method returns a {@link List}, instead of the
50   * {@link java.util.Collection} specified in the {@link Multimap} interface.
51   */
52  @Override
53  List<V> get(@Nullable K key);
54
55  /**
56   * {@inheritDoc}
57   *
58   * <p>Because the values for a given key may have duplicates and follow the
59   * insertion ordering, this method returns a {@link List}, instead of the
60   * {@link java.util.Collection} specified in the {@link Multimap} interface.
61   */
62  @Override
63  List<V> removeAll(@Nullable Object key);
64
65  /**
66   * {@inheritDoc}
67   *
68   * <p>Because the values for a given key may have duplicates and follow the
69   * insertion ordering, this method returns a {@link List}, instead of the
70   * {@link java.util.Collection} specified in the {@link Multimap} interface.
71   */
72  @Override
73  List<V> replaceValues(K key, Iterable<? extends V> values);
74
75  /**
76   * {@inheritDoc}
77   *
78   * <p><b>Note:</b> The returned map's values are guaranteed to be of type
79   * {@link List}. To obtain this map with the more specific generic type
80   * {@code Map<K, List<V>>}, call {@link Multimaps#asMap(ListMultimap)}
81   * instead.
82   */
83  @Override
84  Map<K, Collection<V>> asMap();
85
86  /**
87   * Compares the specified object to this multimap for equality.
88   *
89   * <p>Two {@code ListMultimap} instances are equal if, for each key, they
90   * contain the same values in the same order. If the value orderings disagree,
91   * the multimaps will not be considered equal.
92   *
93   * <p>An empty {@code ListMultimap} is equal to any other empty {@code
94   * Multimap}, including an empty {@code SetMultimap}.
95   */
96  @Override
97  boolean equals(@Nullable Object obj);
98}
99