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
17 package com.google.common.collect;
18
19 import com.google.common.annotations.GwtCompatible;
20 import com.google.errorprone.annotations.CanIgnoreReturnValue;
21 import java.util.Collection;
22 import java.util.Collections;
23 import java.util.Map;
24 import java.util.NavigableSet;
25 import java.util.SortedSet;
26 import org.checkerframework.checker.nullness.qual.Nullable;
27
28 /**
29 * Basic implementation of the {@link SortedSetMultimap} interface. It's a wrapper around {@link
30 * AbstractMapBasedMultimap} that converts the returned collections into sorted sets. The {@link
31 * #createCollection} method must return a {@code SortedSet}.
32 *
33 * @author Jared Levy
34 */
35 @GwtCompatible
36 abstract class AbstractSortedSetMultimap<K, V> extends AbstractSetMultimap<K, V>
37 implements SortedSetMultimap<K, V> {
38 /**
39 * Creates a new multimap that uses the provided map.
40 *
41 * @param map place to store the mapping from each key to its corresponding values
42 */
43 protected AbstractSortedSetMultimap(Map<K, Collection<V>> map) {
44 super(map);
45 }
46
47 @Override
48 abstract SortedSet<V> createCollection();
49
50 @Override
51 SortedSet<V> createUnmodifiableEmptyCollection() {
52 return unmodifiableCollectionSubclass(createCollection());
53 }
54
55 @Override
56 <E> SortedSet<E> unmodifiableCollectionSubclass(Collection<E> collection) {
57 if (collection instanceof NavigableSet) {
58 return Sets.unmodifiableNavigableSet((NavigableSet<E>) collection);
59 } else {
60 return Collections.unmodifiableSortedSet((SortedSet<E>) collection);
61 }
62 }
63
64 @Override
65 Collection<V> wrapCollection(K key, Collection<V> collection) {
66 if (collection instanceof NavigableSet) {
67 return new WrappedNavigableSet(key, (NavigableSet<V>) collection, null);
68 } else {
69 return new WrappedSortedSet(key, (SortedSet<V>) collection, null);
70 }
71 }
72
73 // Following Javadoc copied from Multimap and SortedSetMultimap.
74
75 /**
76 * Returns a collection view of all values associated with a key. If no mappings in the multimap
77 * have the provided key, an empty collection is returned.
78 *
79 * <p>Changes to the returned collection will update the underlying multimap, and vice versa.
80 *
81 * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method
82 * returns a {@link SortedSet}, instead of the {@link Collection} specified in the {@link
83 * Multimap} interface.
84 */
85 @Override
86 public SortedSet<V> get(@Nullable K key) {
87 return (SortedSet<V>) super.get(key);
88 }
89
90 /**
91 * Removes all values associated with a given key. The returned collection is immutable.
92 *
93 * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method
94 * returns a {@link SortedSet}, instead of the {@link Collection} specified in the {@link
95 * Multimap} interface.
96 */
97 @CanIgnoreReturnValue
98 @Override
99 public SortedSet<V> removeAll(@Nullable Object key) {
100 return (SortedSet<V>) super.removeAll(key);
101 }
102
103 /**
104 * Stores a collection of values with the same key, replacing any existing values for that key.
105 * The returned collection is immutable.
106 *
107 * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method
108 * returns a {@link SortedSet}, instead of the {@link Collection} specified in the {@link
109 * Multimap} interface.
110 *
111 * <p>Any duplicates in {@code values} will be stored in the multimap once.
112 */
113 @CanIgnoreReturnValue
114 @Override
115 public SortedSet<V> replaceValues(@Nullable K key, Iterable<? extends V> values) {
116 return (SortedSet<V>) super.replaceValues(key, values);
117 }
118
119 /**
120 * Returns a map view that associates each key with the corresponding values in the multimap.
121 * Changes to the returned map, such as element removal, will update the underlying multimap. The
122 * map does not support {@code setValue} on its entries, {@code put}, or {@code putAll}.
123 *
124 * <p>When passed a key that is present in the map, {@code asMap().get(Object)} has the same
125 * behavior as {@link #get}, returning a live collection. When passed a key that is not present,
126 * however, {@code asMap().get(Object)} returns {@code null} instead of an empty collection.
127 *
128 * <p>Though the method signature doesn't say so explicitly, the returned map has {@link
129 * SortedSet} values.
130 */
131 @Override
132 public Map<K, Collection<V>> asMap() {
133 return super.asMap();
134 }
135
136 /**
137 * {@inheritDoc}
138 *
139 * <p>Consequently, the values do not follow their natural ordering or the ordering of the value
140 * comparator.
141 */
142 @Override
143 public Collection<V> values() {
144 return super.values();
145 }
146
147 private static final long serialVersionUID = 430848587173315748L;
148 }