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.
030     *
031     * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods
032     * each return a {@link List} of values. Though the method signature doesn't say
033     * so explicitly, the map returned by {@link #asMap} has {@code List} values.
034     * 
035     * <p>See the Guava User Guide article on <a href=
036     * "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Multimap">
037     * {@code Multimap}</a>.
038     *
039     * @author Jared Levy
040     * @since 2.0 (imported from Google Collections Library)
041     */
042    @GwtCompatible
043    public interface ListMultimap<K, V> extends Multimap<K, V> {
044      /**
045       * {@inheritDoc}
046       *
047       * <p>Because the values for a given key may have duplicates and follow the
048       * insertion ordering, this method returns a {@link List}, instead of the
049       * {@link java.util.Collection} specified in the {@link Multimap} interface.
050       */
051      @Override
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      @Override
062      List<V> removeAll(@Nullable Object key);
063    
064      /**
065       * {@inheritDoc}
066       *
067       * <p>Because the values for a given key may have duplicates and follow the
068       * insertion ordering, this method returns a {@link List}, instead of the
069       * {@link java.util.Collection} specified in the {@link Multimap} interface.
070       */
071      @Override
072      List<V> replaceValues(K key, Iterable<? extends V> values);
073    
074      /**
075       * {@inheritDoc}
076       *
077       * <p>Though the method signature doesn't say so explicitly, the returned map
078       * has {@link List} values.
079       */
080      @Override
081      Map<K, Collection<V>> asMap();
082    
083      /**
084       * Compares the specified object to this multimap for equality.
085       *
086       * <p>Two {@code ListMultimap} instances are equal if, for each key, they
087       * contain the same values in the same order. If the value orderings disagree,
088       * the multimaps will not be considered equal.
089       *
090       * <p>An empty {@code ListMultimap} is equal to any other empty {@code
091       * Multimap}, including an empty {@code SetMultimap}.
092       */
093      @Override
094      boolean equals(@Nullable Object obj);
095    }