@PreDestroy
 public void destroy() {
   destroyed.incrementAndGet();
   instance.set(null);
   System.err.println("Destroying Hello instance");
   synchronized (instance) {
     instance.notifyAll();
   }
 }
 @PostConstruct
 public void init() {
   created.incrementAndGet();
   instance.set(this);
   System.err.println("Creating Hello instance");
   synchronized (instance) {
     instance.notifyAll();
   }
 }