import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
public class Main {
public static void main(String[] argv) throws Exception {
ReferenceQueue rq = new ReferenceQueue();
WeakReference wr = new WeakReference("string", rq);
while (true) {
Reference r = rq.remove();
if (r == wr) {
System.out.println("no longer referenced");
}
}
}
}