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  
21  import java.util.Collection;
22  import java.util.Comparator;
23  import java.util.Map;
24  import java.util.Set;
25  import java.util.SortedSet;
26  
27  import 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
51  public 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 }