android - How to create listener to the server on thread that was created on service? -

i have android service creates new thread.

@override public int onstartcommand(intent intent, int flags, int startid) {     t = new connectionthread();     t.start();     return service.start_not_sticky; } 

on thread i'm opening socket connection , keeping alive. looks this

@override public void run() {     try {         inetaddress serveraddr = inetaddress.getbyname(server_ip);         socket = new socket(serveraddr, serverport);     } catch (ioexception e) {         e.printstacktrace();     } } 

on thread have method can send json message server. call service , service command called fragment (on buttonclick) , works fine.

public string sendjson() {     jsonobject messagejson = new jsonobject();     jsonobject mjson = new jsonobject();      try {         mjson.put("type", "readytobind");         messagejson.put("deviceid", "mydeviceid");         messagejson.put("allowfastbind", true);         mjson.put("message", messagejson);     } catch (jsonexception e) {         e.printstacktrace();     }      printwriter out = null;     try {         out = new printwriter(new bufferedwriter(new outputstreamwriter(socket.getoutputstream())), true);         out.println(mjson);      } catch (ioexception e) {         e.printstacktrace();     }      return message2; } 

but main problem server giving response in 3 seconds. means can give response instantly or wait 0-3 seconds , give different response.

how should implement listener server? should listen commands recieved server , react application (change current fragment ui).

i tried create second thread on sendjson() method

        mthread = new connectionthread2ndlevel(socket);         mthread.start();         long start = system.currenttimemillis();         long end = start + 3 * 1000; // 3 seconds * 1000 ms/sec         while (system.currenttimemillis() < end){             message2 = mthread.getmessage();         } 

and on thread run() method read , on getmessage() return recieved message.

        scanner = new scanner(socket.getinputstream());         message2thread = scanner.nextline(); 

but freezes application , user nothing can during time. not i've got response server (maybe got response , on while loop read blank line , return back.

so please, can give me advice or example how in right way? great server listener recieve message , instantly initiate changes on fragment (ui).