2018-04-12 4:19 GMT+08:00 Mark Thomas <[email protected]>:
> On 11/04/18 09:50, Funian Li wrote:
> > Dear All,
> >
> > A problem happen when tomcat websocket server was used.
>
> >Exact Tomcat version?
>
> >If not 8.5.30, does the problem still occur if you upgrade to 8.5.30?
>
> >Mark
>
Yes , the exact Tomcat version is 8.5.30, shall i upgrade to tomcat 9.0 ?
Thanks.
Funian Li
>
> A sensor data chart with sampling freqency 50Hz is drawn. Tomcat
> websocket server( Version 8.5) is used to push the data with 20ms
> interval. The server code is as following:
>
> @ServerEndpoint("/websocketendpoint")public class WsServer {private
> Session session;private boolean keepingrunning;private static
> CopyOnWriteArraySet<WsServer> webSocketSet
> = new CopyOnWriteArraySet<WsServer>();
> @OnClosepublic void onClose() {
> System.out.println("Close Connection ...");
> keepingrunning = true;
> webSocketSet.remove(this);}
> @OnOpenpublic void onOpen(Session session) {
> System.out.println("Open Connection ...");
> keepingrunning = true;
> this.session = session;
> webSocketSet.add(this);
> }
> @OnMessagepublic void onMessage(String message, Session session) {
> System.out.println("Message from the client: " + message);
> try {
> Random r = new Random();
> // keep sending data
> while (keepingrunning) {
> int daf = r.nextInt();
> this.session.getBasicRemote().sendText(Integer.toString(daf));
> Thread.sleep(20);
> }
> } catch (Exception ex) {
> ex.printStackTrace();
> }
> System.out.println("end");
> }
> @OnErrorpublic void onError(Throwable e) {
> keepingrunning = true;
> e.printStackTrace();}}
>
> The client is as following:
>
> var ws=new WebSocket("ws://localhost:8080/WebSocketTest/
websocketendpoint");
> function start_webserver(){
> ws.send("ac_1");}
>
> ws.onopen = function(evt) {
> console.log("Connection open ..."); };
>
> ws.onmessage = function(evt) {
> console.log( "Received Message: " + evt.data);
> if(chart.series[0].data.length > 400) {
> chart.series[0].addPoint(parseFloat(evt.data), false, true,
false);
> } else{
> chart.series[0].addPoint(parseFloat(evt.data), false, false,
false);
> }};
>
> ws.onclose = function(evt) {
> console.log("Connection closed.");
> ws.close();};
>
>
> ws.onerror = function (evt) {
> console.log("error: ", evt);
> };
>
>
> function end_webserver(){
> console.log("end the connection");
> ws.close();
> console.log("over");}
> // the button
> <button id="button" onclick="start_webserver()">Start</button>
> <button id="button" onclick="end_webserver()">stop</button>
>
>
> Questions:
>
> When start button clicked, the client can recieve the data to display the
> chart continously. But the stop button clicked , the onclose function both
> on client and server side did not call. It seem that onclose function is
> blocked by the onmessage function because the server keep sending data.
> Another websocket sever is tested and no problem happed. So is is the bug
> of tomcat socketserver ? Thanks.
>
> Regards,
> Skyspeed
>
>
> -
>
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