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Types that extend and augment the Java Collections Framework.
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/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2003-2004 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowledgement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
 *
 * 4. The names "The Jakarta Project", "Commons", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
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 *    permission, please contact [email protected].
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
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 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * .
 */
package org.apache.commons.collections.bag;

import java.util.Set;

import org.apache.commons.collections.Bag;
import org.apache.commons.collections.collection.SynchronizedCollection;
import org.apache.commons.collections.set.SynchronizedSet;

/**
 * Decorates another Bag to synchronize its behaviour
 * for a multi-threaded environment.
 * 
 * Methods are synchronized, then forwarded to the decorated bag.
 * Iterators must be separately synchronized around the loop.
 *
 * @since Commons Collections 3.0
 * @version $Revision: 1.4 $ $Date: 2004/01/14 21:43:08 $
 * 
 * @author Stephen Colebourne
 */
public class SynchronizedBag
        extends SynchronizedCollection implements Bag {

    /**
     * Factory method to create a synchronized bag.
     * 
     * @param bag  the bag to decorate, must not be null
     * @throws IllegalArgumentException if bag is null
     */
    public static Bag decorate(Bag bag) {
        return new SynchronizedBag(bag);
    }
    
    //-----------------------------------------------------------------------
    /**
     * Constructor that wraps (not copies).
     * 
     * @param bag  the bag to decorate, must not be null
     * @throws IllegalArgumentException if bag is null
     */
    protected SynchronizedBag(Bag bag) {
        super(bag);
    }

    /**
     * Constructor that wraps (not copies).
     * 
     * @param bag  the bag to decorate, must not be null
     * @param lock  the lock to use, must not be null
     * @throws IllegalArgumentException if bag is null
     */
    protected SynchronizedBag(Bag bag, Object lock) {
        super(bag, lock);
    }

    protected Bag getBag() {
        return (Bag) collection;
    }
    
    //-----------------------------------------------------------------------
    public boolean add(Object object, int count) {
        synchronized (lock) {
            return getBag().add(object, count);
        }
    }

    public boolean remove(Object object, int count) {
        synchronized (lock) {
            return getBag().remove(object, count);
        }
    }

    public Set uniqueSet() {
        synchronized (lock) {
            Set set = getBag().uniqueSet();
            return new SynchronizedBagSet(set, lock);
        }
    }

    public int getCount(Object object) {
        synchronized (lock) {
            return getBag().getCount(object);
        }
    }
    
    //-----------------------------------------------------------------------
    /**
     * Synchronized Set for the Bag class.
     */
    class SynchronizedBagSet extends SynchronizedSet {
        SynchronizedBagSet(Set set, Object lock) {
            super(set, lock);
        }
    }

}