org.apache.commons.collections15.map.HashedMap.java Source code

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Here is the source code for org.apache.commons.collections15.map.HashedMap.java

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// GenericsNote: Converted.
/*
 *  Copyright 2003-2004 The Apache Software Foundation
 *
 *  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 org.apache.commons.collections15.map;

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

/**
 * A <code>Map</code> implementation that is a general purpose alternative
 * to <code>HashMap</code>.
 * <p/>
 * This implementation improves on the JDK1.4 HashMap by adding the
 * {@link org.apache.commons.collections15.MapIterator MapIterator}
 * functionality and many methods for subclassing.
 * <p/>
 *
 * @author Matt Hall, John Watkinson, Stephen Colebourne
 * @version $Revision: 1.1 $ $Date: 2005/10/11 17:05:32 $
 * @since Commons Collections 3.0
 */
public class HashedMap<K, V> extends AbstractHashedMap<K, V> implements Serializable, Cloneable {

    /**
     * Serialisation version
     */
    private static final long serialVersionUID = -1788199231038721040L;

    /**
     * Constructs a new empty map with default size and load factor.
     */
    public HashedMap() {
        super(DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_THRESHOLD);
    }

    /**
     * Constructs a new, empty map with the specified initial capacity.
     *
     * @param initialCapacity the initial capacity
     * @throws IllegalArgumentException if the initial capacity is less than one
     */
    public HashedMap(int initialCapacity) {
        super(initialCapacity);
    }

    /**
     * Constructs a new, empty map with the specified initial capacity and
     * load factor.
     *
     * @param initialCapacity the initial capacity
     * @param loadFactor      the load factor
     * @throws IllegalArgumentException if the initial capacity is less than one
     * @throws IllegalArgumentException if the load factor is less than zero
     */
    public HashedMap(int initialCapacity, float loadFactor) {
        super(initialCapacity, loadFactor);
    }

    /**
     * Constructor copying elements from another map.
     *
     * @param map the map to copy
     * @throws NullPointerException if the map is null
     */
    public HashedMap(Map<? extends K, ? extends V> map) {
        super(map);
    }

    //-----------------------------------------------------------------------
    /**
     * Clones the map without cloning the keys or values.
     *
     * @return a shallow clone
     */
    public Object clone() {
        return super.clone();
    }

    /**
     * Write the map out using a custom routine.
     */
    private void writeObject(ObjectOutputStream out) throws IOException {
        out.defaultWriteObject();
        doWriteObject(out);
    }

    /**
     * Read the map in using a custom routine.
     */
    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        in.defaultReadObject();
        doReadObject(in);
    }

}