java - CountDownTimer not working at all -

i trying run countdowntimer inside thread, won't work..

so in mainactivitys oncreate start on button click that:

public void onclick(final view v) {     log.d("main", "onclick");     runonuithread(runner); } 

runner instance of class implements runnable:

private countdownlatch donesignal = new countdownlatch(1); @override public void run() {     log.d("wr", "run");     this.countdown(20);     log.d("wr", "waiting");     try {         donesignal.await();     } catch (final interruptedexception ex) {         log.e("wr", ex.getmessage(), ex);     }     log.d("wr", "waited"); } private void countdown(int time) {     final countdowntimer timer = new countdowntimer(time * 1000, 1000) {          @override         public void ontick(final long millisuntilfinished) {             log.d("wr", "ontick");         }          @override         public void onfinish() {             log.d("wr", "onfinish");             donesignal.countdown();         }     };     log.d("wr", "starting");     timer.start();     log.d("wr", "started"); } 

with code, application freezes after logging onclick, run , starting. changing runonuithread(runner) new thread(runner).start(); makes application crash after logging onclick no more output.

some research said countdowntimer needs run on ui-thread due use of handler. freezes.

when remove entire thread stuff , call runner.run(); in buttons onclick (also removing implements runnable in runner instance) following log entries: onclick, run, starting, started, waiting. nothing happens, if timer not run, no call of ontick method.

how can fix countdowntimer?

countdowntimer runs on ui thread, , has run on ui thread, because internally uses handler, in turns neead looper. runonuithread(runner); whatever runner does, runs on ui thread.

private countdownlatch donesignal = new countdownlatch(1); 

calling await() on ui thread block it, , since countdown() runs on same thread practically dead-locked app