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

com.groupbyinc.common.apache.commons.collections4.bidimap.DualHashBidiMap Maven / Gradle / Ivy

There is a newer version: 198
Show newest version
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.commons.collections4.bidimap;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.collections4.BidiMap;

/**
 * Implementation of {@link BidiMap} that uses two {@link HashMap} instances.
 * 

* Two {@link HashMap} instances are used in this class. * This provides fast lookups at the expense of storing two sets of map entries. * Commons Collections would welcome the addition of a direct hash-based * implementation of the {@link BidiMap} interface. *

* NOTE: From Commons Collections 3.1, all subclasses will use {@link HashMap} * and the flawed createMap method is ignored. * * @since 3.0 * @version $Id: DualHashBidiMap.java 1533984 2013-10-20 21:12:51Z tn $ */ public class DualHashBidiMap extends AbstractDualBidiMap implements Serializable { /** Ensure serialization compatibility */ private static final long serialVersionUID = 721969328361808L; /** * Creates an empty HashBidiMap. */ public DualHashBidiMap() { super(new HashMap(), new HashMap()); } /** * Constructs a HashBidiMap and copies the mappings from * specified Map. * * @param map the map whose mappings are to be placed in this map */ public DualHashBidiMap(final Map map) { super(new HashMap(), new HashMap()); putAll(map); } /** * Constructs a HashBidiMap that decorates the specified maps. * * @param normalMap the normal direction map * @param reverseMap the reverse direction map * @param inverseBidiMap the inverse BidiMap */ protected DualHashBidiMap(final Map normalMap, final Map reverseMap, final BidiMap inverseBidiMap) { super(normalMap, reverseMap, inverseBidiMap); } /** * Creates a new instance of this object. * * @param normalMap the normal direction map * @param reverseMap the reverse direction map * @param inverseBidiMap the inverse BidiMap * @return new bidi map */ @Override protected BidiMap createBidiMap(final Map normalMap, final Map reverseMap, final BidiMap inverseBidiMap) { return new DualHashBidiMap(normalMap, reverseMap, inverseBidiMap); } // Serialization //----------------------------------------------------------------------- private void writeObject(final ObjectOutputStream out) throws IOException { out.defaultWriteObject(); out.writeObject(normalMap); } private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException { in.defaultReadObject(); normalMap = new HashMap(); reverseMap = new HashMap(); @SuppressWarnings("unchecked") // will fail at runtime if stream is incorrect final Map map = (Map) in.readObject(); putAll(map); } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy