WebSocket endpoint as a Singleton EJB

SingletonEndpoint.java

@Singleton
@ServerEndpoint("/singleton/")
public class SingletonEndpoint {
    @OnOpen
    public void onopen(Session s) throws IOException {
        s.getBasicRemote().sendText(String.valueOf(hashCode()));
    }
    @PreDestroy
    public void onDestroy() {
        System.out.println("Singleton bean " + hashCode() + " will be destroyed");
    }
    @OnClose
    public void onClose(Session session, CloseReason closeReason) {
        System.out.println("Closed " + session.getId() + " due to " + closeReason.getCloseCode());
    }
}