Re: [undertow-dev] Correctly shutting down a websocket handler

Hi Robin: I'm new to WebSockets but I'm glad to share what has been working for me. My use cases are currently via Java SE not the Web so this may not apply. I'm migrating a bunch of data from an old system and really just pounding on Undertow to see how it will behave when I'm ready to build my production application. And, I in no way claim this is a best practice. But, maybe you will find it useful. Anyway, I add three additional methods to each of my deocorated websockets (clients) two of which I call from other objects as needed. With this approach I'm not seeing any data loss. Seem to be getting timely responses from the server side WebSocket. And, always get a nice clean [1000] close codes. setup() tearDown() sendWorktoServer() public void sendWorkToServer(Object obj) { //logger.info(this.getClass().getSimpleName() + " >>> Enter sendWorkToServer"); if (webSocketSession == null || !webSocketSession.isOpen()) { setUp(); } if (obj == null || obj.getId() == null || obj.getId().isEmpty()) { return; } ObjectMapper mapper = new ObjectMapper(); String json = null; try { json = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(obj); logger.info(json); webSocketSession.getAsyncRemote().sendText(json); //messageLatch.await(500, TimeUnit.MILLISECONDS); } catch (JsonProcessingException e) { e.printStackTrace(); } logger.info("Socket is open: " + webSocketSession.isOpen()); logger.info("Exit sendWorkToServer"); } private boolean setUp() { //Called if needed inside sendWorkToServer() method try { websocketServerURI = serverSocketURI.getAddCfgStructureWsUri(); // Get Correct URI Development vs Production logger.info("URI: " + websocketServerURI.toString()); webSocketContainer = ContainerProvider.getWebSocketContainer(); // WebSocket Container webSocketSession = webSocketContainer.connectToServer(this.getClass(), websocketServerURI); // Connect to the Server if (!webSocketSession.isOpen()) { messageLatch.await(10, TimeUnit.SECONDS); } } catch (DeploymentException e) { e.printStackTrace(); return false; } catch (IOException e) { e.printStackTrace(); return false; } catch (InterruptedException e) { e.printStackTrace(); } return true; } public boolean tearDown() { if (webSocketSession != null) { if (webSocketSession.isOpen()) { try { webSocketSession.close(); } catch (IOException e) { e.printStackTrace(); return false; } } } webSocketSession = null; webSocketContainer = null; websocketServerURI = null; serverSocketURI = null; return true; } So, inside my other object the code looks something like... WebSocketClient wcs = new WebSocketClient(); wcs.sendWorkToServer(Object obj); // More work and activities wcs.teardown(); wcs = null; Also, what might be helpful is to add a custom method that just return the status of your websocketclient session and then call teardown() as needed. I hope that helps a bit... In my scenario I take some extra steps to control the life cycle so I don't really have to detect status. Cordially, Dennis On Thu, Nov 19, 2015 at 1:12 PM, Robin Anil <robin.anil(a)gmail.com&gt; wrote: -- [image: LinkedIn] <https://www.linkedin.com/in/gesker> <https://www.facebook.com/gesker>[image: Wordpress] <https://gesker.wordpress.com/>[image: Facebook][image: Twitter] <https://twitter.com/gesker> <https://gesker.wordpress.com/> <http://www.gesker.com> <https://google.com/+DennisGesker>[image: Family Home Page][image: Public Encryption Key] <https://pgp.mit.edu/pks/lookup?search=dennis%40gesker.com&op=index>...: dennis(a)gesker.com] <dennis(a)gesker.com&gt; “Be without fear in the face of your enemies. Be brave and upright that God may love thee. Speak the truth always, even if it leads to your death. Safeguard the helpless and do no wrong – that is your oath.”* -The Knight’s Oath (Kingdom of Heaven)*