java - Asynctask and Handler class - can't share variable -

i have service includes asynctask , handler classes. asynctask , handler should share variable. use static volatile variable issendmessage because think there 2 threads, i'm not sure. problem variable in while loop doesn't change. don't know mistake is. here snippet of code.

    public class services extends service  {      static volatile boolean issendmessage = false;       @override         public ibinder onbind(intent intent) {             return null;         }       @override         public int onstartcommand (intent intent, int flags, int startid) {              new connectionserverasynctask().execute();              return service.start_sticky;     }      public class connectionserverasynctask extends asynctask<void, result, void> {     private boolean finish = false;       @override      protected void onpreexecute() {        super.onpreexecute();      }      @override     protected void doinbackground(void... params) {       while(!finish){          log.i("issendmessage",string.valueof(issendmessage));           }     }        @override     protected void onpostexecute(void avoid) {         super.onpostexecute(avoid);     }    }      public static class messagehandler extends handler{              @override             public void handlemessage(message msg) {                log.i("messagehandler","handlemessage");                issendmessage = true;                           }         }       } 

onpostexecute() automatically uses ui thread there's not need use handler in combination async task. write code want executed there anywhere else.

also loop while(!finish), didn't see anyplace finish set true.