Java example source code file (SetMultimap.java)

This example Java source code file (SetMultimap.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

annotation, canignorereturnvalue, collection, gwtcompatible, iterable, multimap, object, override, set, setmultimap, util

The SetMultimap.java Java example source code

/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

import java.util.Collection;
import java.util.Map;
import java.util.Set;

import javax.annotation.Nullable;

/**
 * A {@code Multimap} that cannot hold duplicate key-value pairs. Adding a
 * key-value pair that's already in the multimap has no effect. See the {@link
 * Multimap} documentation for information common to all multimaps.
 *
 * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods
 * each return a {@link Set} of values, while {@link #entries} returns a {@code
 * Set} of map entries. Though the method signature doesn't say so explicitly,
 * the map returned by {@link #asMap} has {@code Set} values.
 *
 * <p>If the values corresponding to a single key should be ordered according to
 * a {@link java.util.Comparator} (or the natural order), see the
 * {@link SortedSetMultimap} subinterface.
 *
 * <p>Since the value collections are sets, the behavior of a {@code SetMultimap}
 * is not specified if key <em>or value objects already present in the
 * multimap change in a manner that affects {@code equals} comparisons.
 * Use caution if mutable objects are used as keys or values in a
 * {@code SetMultimap}.
 *
 * <p>See the Guava User Guide article on  {
  /**
   * {@inheritDoc}
   *
   * <p>Because a {@code SetMultimap} has unique values for a given key, this
   * method returns a {@link Set}, instead of the {@link java.util.Collection}
   * specified in the {@link Multimap} interface.
   */
  @Override
  Set<V> get(@Nullable K key);

  /**
   * {@inheritDoc}
   *
   * <p>Because a {@code SetMultimap} has unique values for a given key, this
   * method returns a {@link Set}, instead of the {@link java.util.Collection}
   * specified in the {@link Multimap} interface.
   */
  @CanIgnoreReturnValue
  @Override
  Set<V> removeAll(@Nullable Object key);

  /**
   * {@inheritDoc}
   *
   * <p>Because a {@code SetMultimap} has unique values for a given key, this
   * method returns a {@link Set}, instead of the {@link java.util.Collection}
   * specified in the {@link Multimap} interface.
   *
   * <p>Any duplicates in {@code values} will be stored in the multimap once.
   */
  @CanIgnoreReturnValue
  @Override
  Set<V> replaceValues(K key, Iterable values);

  /**
   * {@inheritDoc}
   *
   * <p>Because a {@code SetMultimap} has unique values for a given key, this
   * method returns a {@link Set}, instead of the {@link java.util.Collection}
   * specified in the {@link Multimap} interface.
   */
  @Override
  Set<Map.Entry entries();

  /**
   * {@inheritDoc}
   *
   * <p>Note: The returned map's values are guaranteed to be of type
   * {@link Set}. To obtain this map with the more specific generic type
   * {@code Map<K, Set}, call {@link Multimaps#asMap(SetMultimap)} instead.
   */
  @Override
  Map<K, Collection asMap();

  /**
   * Compares the specified object to this multimap for equality.
   *
   * <p>Two {@code SetMultimap} instances are equal if, for each key, they
   * contain the same values. Equality does not depend on the ordering of keys
   * or values.
   *
   * <p>An empty {@code SetMultimap} is equal to any other empty {@code
   * Multimap}, including an empty {@code ListMultimap}.
   */
  @Override
  boolean equals(@Nullable Object obj);
}