All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.google.common.collect.EnumHashBiMap Maven / Gradle / Ivy

Go to download

Guava is a suite of core and expanded libraries that include utility classes, google's collections, io classes, and much much more.

There is a newer version: 33.3.0-jre
Show newest version
/*
 * 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 static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.EnumMap;
import java.util.HashMap;
import java.util.Map;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@code BiMap} backed by an {@code EnumMap} instance for keys-to-values, and a {@code HashMap}
 * instance for values-to-keys. Null keys are not permitted, but null values are. An {@code
 * EnumHashBiMap} and its inverse are both serializable.
 *
 * 

See the Guava User Guide article on {@code BiMap}. * * @author Mike Bostock * @since 2.0 */ @GwtCompatible(emulated = true) public final class EnumHashBiMap, V> extends AbstractBiMap { private transient Class keyType; /** * Returns a new, empty {@code EnumHashBiMap} using the specified key type. * * @param keyType the key type */ public static , V> EnumHashBiMap create(Class keyType) { return new EnumHashBiMap<>(keyType); } /** * Constructs a new bimap with the same mappings as the specified map. If the specified map is an * {@code EnumHashBiMap} or an {@link EnumBiMap}, the new bimap has the same key type as the input * bimap. Otherwise, the specified map must contain at least one mapping, in order to determine * the key type. * * @param map the map whose mappings are to be placed in this map * @throws IllegalArgumentException if map is not an {@code EnumBiMap} or an {@code EnumHashBiMap} * instance and contains no mappings */ public static , V> EnumHashBiMap create(Map map) { EnumHashBiMap bimap = create(EnumBiMap.inferKeyType(map)); bimap.putAll(map); return bimap; } private EnumHashBiMap(Class keyType) { super( new EnumMap(keyType), Maps.newHashMapWithExpectedSize(keyType.getEnumConstants().length)); this.keyType = keyType; } // Overriding these 3 methods to show that values may be null (but not keys) @Override K checkKey(K key) { return checkNotNull(key); } @CanIgnoreReturnValue @Override public V put(K key, @Nullable V value) { return super.put(key, value); } @CanIgnoreReturnValue @Override public V forcePut(K key, @Nullable V value) { return super.forcePut(key, value); } /** Returns the associated key type. */ public Class keyType() { return keyType; } /** * @serialData the key class, number of entries, first key, first value, second key, second value, * and so on. */ @GwtIncompatible // java.io.ObjectOutputStream private void writeObject(ObjectOutputStream stream) throws IOException { stream.defaultWriteObject(); stream.writeObject(keyType); Serialization.writeMap(this, stream); } @SuppressWarnings("unchecked") // reading field populated by writeObject @GwtIncompatible // java.io.ObjectInputStream private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException { stream.defaultReadObject(); keyType = (Class) stream.readObject(); setDelegates( new EnumMap(keyType), new HashMap(keyType.getEnumConstants().length * 3 / 2)); Serialization.populateMap(this, stream); } @GwtIncompatible // only needed in emulated source. private static final long serialVersionUID = 0; }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy