SortedSetMultimap.java revision 0888a09821a98ac0680fad765217302858e70fa4 
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.Comparator;
23import java.util.Map;
24import java.util.Set;
25import java.util.SortedSet;
26
27import javax.annotation.Nullable;
28
29/**
30 * A {@code SetMultimap} whose set of values for a given key are kept sorted;
31 * that is, they comprise a {@link SortedSet}. It cannot hold duplicate
32 * key-value pairs; adding a key-value pair that's already in the multimap has
33 * no effect. This interface does not specify the ordering of the multimap's
34 * keys. See the {@link Multimap} documentation for information common to all
35 * multimaps.
36 *
37 * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods
38 * each return a {@link SortedSet} of values, while {@link Multimap#entries()}
39 * returns a {@link Set} of map entries. Though the method signature doesn't say
40 * so explicitly, the map returned by {@link #asMap} has {@code SortedSet}
41 * values.
42 *
43 * <p>See the Guava User Guide article on <a href=
44 * "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multimap">
45 * {@code Multimap}</a>.
46 *
47 * @author Jared Levy
48 * @since 2.0 (imported from Google Collections Library)
49 */
50@GwtCompatible
51public interface SortedSetMultimap<K, V> extends SetMultimap<K, V> {
52  // Following Javadoc copied from Multimap.
53
54  /**
55   * Returns a collection view of all values associated with a key. If no
56   * mappings in the multimap have the provided key, an empty collection is
57   * returned.
58   *
59   * <p>Changes to the returned collection will update the underlying multimap,
60   * and vice versa.
61   *
62   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
63   * key, this method returns a {@link SortedSet}, instead of the
64   * {@link java.util.Collection} specified in the {@link Multimap} interface.
65   */
66  @Override
67  SortedSet<V> get(@Nullable K key);
68
69  /**
70   * Removes all values associated with a given key.
71   *
72   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
73   * key, this method returns a {@link SortedSet}, instead of the
74   * {@link java.util.Collection} specified in the {@link Multimap} interface.
75   */
76  @Override
77  SortedSet<V> removeAll(@Nullable Object key);
78
79  /**
80   * Stores a collection of values with the same key, replacing any existing
81   * values for that key.
82   *
83   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
84   * key, this method returns a {@link SortedSet}, instead of the
85   * {@link java.util.Collection} specified in the {@link Multimap} interface.
86   *
87   * <p>Any duplicates in {@code values} will be stored in the multimap once.
88   */
89  @Override
90  SortedSet<V> replaceValues(K key, Iterable<? extends V> values);
91
92  /**
93   * Returns a map view that associates each key with the corresponding values
94   * in the multimap. Changes to the returned map, such as element removal, will
95   * update the underlying multimap. The map does not support {@code setValue()}
96   * on its entries, {@code put}, or {@code putAll}.
97   *
98   * <p>When passed a key that is present in the map, {@code
99   * asMap().get(Object)} has the same behavior as {@link #get}, returning a
100   * live collection. When passed a key that is not present, however, {@code
101   * 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
104   * {@link SortedSet}. To obtain this map with the more specific generic type
105   * {@code Map<K, SortedSet<V>>}, call
106   * {@link Multimaps#asMap(SortedSetMultimap)} instead.
107   */
108  @Override Map<K, Collection<V>> asMap();
109
110  /**
111   * Returns the comparator that orders the multimap values, with {@code null}
112   * indicating that natural ordering is used.
113   */
114  Comparator<? super V> valueComparator();
115}
116