Hello,

I really need some help with my program. I have to implement an object pool that uses phantom references to collect objects abandoned by client threads. This is what I have. I'm really not sure about this implementation. Any help would be greatly appreciated.

class ObjectPool<T extends CloneableObject<T>> {

  private Queue<T> pool;

  private List references = new ArrayList();

  private ReferenceQueue rq = new ReferenceQueue();

  private CloneableObject<T> prototype

  public ObjectPool(CloneableObject<T> prototype) {

    this.prototype = prototype;

    pool = new LinkedList<T>();

    new PhantomThread().start();

  }

  public T borrowObject() {   

    T o;

    synchronized(this) {

      if (pool.isEmpty()) {

        o = prototype.clone();   

      }

      else {

        o = pool.remove();

      }

      PhantomReference ref = new PhantomReference(o, rq);

      references.add(ref);

      return o;

    }

  }

  class PhantomThread implements Runnable {

    Thread thread;

    public PhantomThread() {

      thread = new Thread(this);

    }

    public void start() {

      thread.start();

    }

    public void run() {

      Field f;

      Reference<T> ref;

      try {

        f = Reference.class.getDeclaredField("referent");

        while(true) {    

          ref = rq.remove();

          references.remove(ref);

          f.setAccessible(true);

          T o = (T) f.get(ref);

          if(o != null) {

            pool.add(object);

          }

          f.setAccessible(false);

        }

      } catch(Exception ex) {

        ex.printStackTrace();

      }       

    }

  }

}