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;
020
021import java.util.Collection;
022import java.util.Comparator;
023import java.util.Map;
024import java.util.Set;
025import java.util.SortedSet;
026
027import javax.annotation.Nullable;
028
029/**
030 * A {@code SetMultimap} whose set of values for a given key are kept sorted;
031 * that is, they comprise a {@link SortedSet}. It cannot hold duplicate
032 * key-value pairs; adding a key-value pair that's already in the multimap has
033 * no effect. This interface does not specify the ordering of the multimap's
034 * keys. See the {@link Multimap} documentation for information common to all
035 * multimaps.
036 *
037 * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods
038 * each return a {@link SortedSet} of values, while {@link Multimap#entries()}
039 * returns a {@link Set} of map entries. Though the method signature doesn't say
040 * so explicitly, the map returned by {@link #asMap} has {@code SortedSet}
041 * values.
042 *
043 * <p>See the Guava User Guide article on <a href=
044 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap">
045 * {@code Multimap}</a>.
046 *
047 * @author Jared Levy
048 * @since 2.0
049 */
050@GwtCompatible
051public interface SortedSetMultimap<K, V> extends SetMultimap<K, V> {
052  // Following Javadoc copied from Multimap.
053
054  /**
055   * Returns a collection view of all values associated with a key. If no
056   * mappings in the multimap have the provided key, an empty collection is
057   * returned.
058   *
059   * <p>Changes to the returned collection will update the underlying multimap,
060   * and vice versa.
061   *
062   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
063   * key, this method returns a {@link SortedSet}, instead of the
064   * {@link java.util.Collection} specified in the {@link Multimap} interface.
065   */
066  @Override
067  SortedSet<V> get(@Nullable K key);
068
069  /**
070   * Removes all values associated with a given key.
071   *
072   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
073   * key, this method returns a {@link SortedSet}, instead of the
074   * {@link java.util.Collection} specified in the {@link Multimap} interface.
075   */
076  @Override
077  SortedSet<V> removeAll(@Nullable Object key);
078
079  /**
080   * Stores a collection of values with the same key, replacing any existing
081   * values for that key.
082   *
083   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
084   * key, this method returns a {@link SortedSet}, instead of the
085   * {@link java.util.Collection} specified in the {@link Multimap} interface.
086   *
087   * <p>Any duplicates in {@code values} will be stored in the multimap once.
088   */
089  @Override
090  SortedSet<V> replaceValues(K key, Iterable<? extends V> values);
091
092  /**
093   * Returns a map view that associates each key with the corresponding values
094   * in the multimap. Changes to the returned map, such as element removal, will
095   * update the underlying multimap. The map does not support {@code setValue()}
096   * on its entries, {@code put}, or {@code putAll}.
097   *
098   * <p>When passed a key that is present in the map, {@code
099   * 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
109  Map<K, Collection<V>> asMap();
110
111  /**
112   * Returns the comparator that orders the multimap values, with {@code null}
113   * indicating that natural ordering is used.
114   */
115  Comparator<? super V> valueComparator();
116}