Lifecycle events

As shown previously, the @OnMessage lifecycle method is used to handle the primary communication event, which is the delivery of a new message. Other lifecycle events are often used to handle other events of interest. The following table shows the four lifecycle events that are triggered by the WebSockets endpoint:

Annotation	Event	Example
@OnOpen	Connection opened	@OnOpen public void open(Session session, EndpointConfig conf) { }
@OnClose	Connection closed	@OnClose public void close(Session session, CloseReason reason) { }
@OnMessage	Message arrived	@OnMessage public void message(Session session, String msg) { }
@OnError	Connection error	@OnError public void error(Session session, Throwable error) { }