Source Code : A bag of weakly referenced objects

Java Is Open Source Programming Language You Can Download From Java and Java Libraries From http://www.oracle.com. Click Here to download
We provide this code related to title for you to solve your developing problem easily. Libraries which is import in this program you can download from http://www.oracle.com. Click Here or search from google with Libraries Name you get jar file related it

A bag of weakly referenced objects

   

/*
 * Copyright (c) 1998 - 2005 Versant Corporation
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * Versant Corporation - initial API and implementation
 */

import java.util.HashSet;
import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.lang.ref.Reference;

/**
 * This maintains a bag of weakly referenced objects. The clean method
 * must be called from time to time to get rid of the objects that the
 * garbage collector wants to nuke. This class is not synchronized.
 */
public final class WeakBag {

    private HashSet set = new HashSet();
    private ReferenceQueue refQueue = new ReferenceQueue();

    public WeakBag() {
    }

    /**
     * Add o to the bag and return the WeakReference that can be used to
     * remove it.
     */
    public WeakReference add(Object o) {
        WeakReference ans = new WeakReference(o, refQueue);
        set.add(ans);
        return ans;
    }

    /**
     * Remove o from the bag.
     */
    public void remove(Reference o) {
        set.remove(o);
    }

    /**
     * Get the approximate number of objects in the bag.
     */
    public int size() {
        return set.size();
    }

    /**
     * Get all the objects still in the bag.
     */
    public List values() {
        ArrayList a = new ArrayList(set.size());
        for (Iterator i = set.iterator(); i.hasNext(); ) {
            WeakReference r = (WeakReference)i.next();
            Object o = r.get();
            if (o != null) a.add(o);
        }
        return a;
    }

    /**
     * Get rid of objects in the bag that the garbage collector wants to
     * nuke. This does not block.
     */
    public void clean() {
        for (;;) {
            Object r = refQueue.poll();
            if (r == null) return;
            set.remove(r);
        }
    }

}

   
    
    
  

Thank with us