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    
017    package com.google.common.collect;
018    
019    import com.google.common.annotations.GwtCompatible;
020    
021    import java.util.Collection;
022    import java.util.List;
023    import java.util.Map;
024    
025    import javax.annotation.Nullable;
026    
027    /**
028     * A {@code Multimap} that can hold duplicate key-value pairs and that maintains
029     * the insertion ordering of values for a given key. See the {@link Multimap}
030     * documentation for information common to all multimaps.
031     *
032     * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods
033     * each return a {@link List} of values. Though the method signature doesn't say
034     * so explicitly, the map returned by {@link #asMap} has {@code List} values.
035     * 
036     * <p>See the Guava User Guide article on <a href=
037     * "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multimap">
038     * {@code Multimap}</a>.
039     *
040     * @author Jared Levy
041     * @since 2.0 (imported from Google Collections Library)
042     */
043    @GwtCompatible
044    public interface ListMultimap<K, V> extends Multimap<K, V> {
045      /**
046       * {@inheritDoc}
047       *
048       * <p>Because the values for a given key may have duplicates and follow the
049       * insertion ordering, this method returns a {@link List}, instead of the
050       * {@link java.util.Collection} specified in the {@link Multimap} interface.
051       */
052      List<V> get(@Nullable K key);
053    
054      /**
055       * {@inheritDoc}
056       *
057       * <p>Because the values for a given key may have duplicates and follow the
058       * insertion ordering, this method returns a {@link List}, instead of the
059       * {@link java.util.Collection} specified in the {@link Multimap} interface.
060       */
061      List<V> removeAll(@Nullable Object key);
062    
063      /**
064       * {@inheritDoc}
065       *
066       * <p>Because the values for a given key may have duplicates and follow the
067       * insertion ordering, this method returns a {@link List}, instead of the
068       * {@link java.util.Collection} specified in the {@link Multimap} interface.
069       */
070      List<V> replaceValues(K key, Iterable<? extends V> values);
071    
072      /**
073       * {@inheritDoc}
074       *
075       * <p>Though the method signature doesn't say so explicitly, the returned map
076       * has {@link List} values.
077       */
078      Map<K, Collection<V>> asMap();
079    
080      /**
081       * Compares the specified object to this multimap for equality.
082       *
083       * <p>Two {@code ListMultimap} instances are equal if, for each key, they
084       * contain the same values in the same order. If the value orderings disagree,
085       * the multimaps will not be considered equal.
086       *
087       * <p>An empty {@code ListMultimap} is equal to any other empty {@code
088       * Multimap}, including an empty {@code SetMultimap}.
089       */
090      boolean equals(@Nullable Object obj);
091    }