javafx - How to wait cancellation of task after Service#cancel? -

look @ example:

package sample;  import javafx.application.application; import javafx.application.platform; import javafx.concurrent.service; import javafx.concurrent.task; import javafx.stage.stage;  public class main extends application {      //notice: class in **other file** (here example)     private static class myservice extends service {         @override         protected task createtask() {             return new task() {                 @override                 protected object call() throws exception {                     system.out.println("service: start");                      while(true) {                         system.out.println("service: iteration");                          // thread.sleep(3000); // raise interruptedexception after cancel, how such code (it won't raise exception):                          for(long = 0; < 1_000_000_000; i++) {                         }                          if (iscancelled())                             break;                     }                      system.out.println("service: end");                      return null;                 }             };         }     }      @override     public void start(stage primarystage) throws exception {         myservice myservice = new myservice();         myservice.start();          thread.sleep(5000);          myservice.cancel();          system.out.println(myservice.getstate()); // here `cancelled` task isn't finished yet.          // <--- how wait cancellation of task here?          system.out.println("this command must called after `service: end`");          platform.exit();     }      public static void main(string[] args) {         launch(args);     } } 

as known call of service#cancel doesn't wait cancellation of task. so, want block main thread , await cancellation of task. how can it?

p.s.

looks service doesn't provide callback/event handler check real cancellation of task. right?

by default, service.cancel() interrupts task. interruptedexception must raised , task terminated (forcefully).

one thing store created task in global variable in myservice class , override cancel method this:

class myservice extends service {      private task t;      @override     public boolean cancel() {         if (t != null) {             return t.cancel(false);         } else {             return false;         }     }      @override     protected task createtask() {         t = new task() { /* ... */ };         return t;     } } 

the rest easy. add change listener service state property (or use setoncanceled() method) , whatever want after state change, in callback.