The Java Developers Almanac 1.4

e107. Determining When an Object Is No Longer Used

    // Create the weak reference.
    ReferenceQueue rq = new ReferenceQueue();
    WeakReference wr = new WeakReference(object, rq);
    
    // Wait for all the references to the object.
    try {
        while (true) {
            Reference r = rq.remove();
            if (r == wr) {
                // Object is no longer referenced.
            }
        }
    } catch (InterruptedException e) {
    }

Related Examples

e106. Holding onto an Object Until Memory Becomes Low
e108. Determining When an Object Will Be Reclaimed


© 2002 Addison-Wesley.