java - Spring RestTemplate - Log on request sometimes hangs awaiting response -

i use rest template in java client log onto server , receive required headers upgrade connection secure websocket.

here code:

private static void loginandsavejsessionidcookie(final string user, final string password, final httpheaders headerstoupdate) {         string url = "http://localhost:" + port + "/websocket-services/login.html";         new resttemplate().execute(url, httpmethod.post,                 new requestcallback() {                     @override                      public void dowithrequest(clienthttprequest request) throws ioexception {                         system.out.println("start login attempt");                         multivaluemap<string, string> map = new linkedmultivaluemap<>();                         map.add("username", user);                         map.add("password", password);                         new formhttpmessageconverter().write(map, mediatype.application_form_urlencoded, request);                     }                 },                 new responseextractor<object>() {                     @override                     public object extractdata(clienthttpresponse response) throws ioexception {                         system.out.println("got login repsonse");                         headerstoupdate.add("cookie", response.getheaders().getfirst("set-cookie"));                         return null;                     }                 });     } 

this works, (especially after websocket connection has timed out) there no response server , client stops responding while method hangs awaiting response.

could suggest fix or work around ? causes client freeze completely, requiring force close.

to async code threading best way , can use executorservice specify timeout wish have. following 2 options available per need (pls chk api know difference between them) :-

<t> list<future<t>> invokeall(collection<? extends callable<t>> tasks,                                   long timeout, timeunit unit)         throws interruptedexception; 

or

<t> t invokeany(collection<? extends callable<t>> tasks,                     long timeout, timeunit unit)         throws interruptedexception, executionexception, timeoutexception;