Android: How do I stop Runnable?

Question

I tried this way:

private Runnable changeColor = new Runnable() {
   private boolean killMe=false;
   public void run() {
       //some work
       if(!killMe) color_changer.postDelayed(changeColor, 150);
   }
   public void kill(){
       killMe=true;
   }
};

but I can't access kill() method!

score 57 · Accepted Answer · edited Oct 03 '18 at 05:11

57

Instead implement your own thread.kill() mechanism, using existing API provided by the SDK. Manage your thread creation within a threadpool, and use Future.cancel() to kill the running thread:

ExecutorService executorService = Executors.newSingleThreadExecutor();
Runnable longRunningTask = new Runnable();

// submit task to threadpool:
Future longRunningTaskFuture = executorService.submit(longRunningTask);

... ...
// At some point in the future, if you want to kill the task:
longRunningTaskFuture.cancel(true);
... ...

Cancel method will behave differently based on your task running state, check the API for more details.

edited Oct 03 '18 at 05:11

Bertram Gilfoyle

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answered Feb 27 '12 at 00:47

yorkw

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If `longRunningTask` contains a list of tasks, how can I abort certain task's execution? There may be lots of thread running concurrently. – Alston Oct 23 '14 at 09:33
@DanielWilson I have a same problem. did you solve that? – Mahdi Jul 08 '15 at 09:31
.cancel method not found – Mayur Coceptioni Jul 30 '19 at 12:10
@Alston This is possible but you need to keep track of references. A list won‘t work, because of the return value of `void run()`. Collections do not store null. You could probably use a `Map` to accumulate references to each Runnable when you `submit(Runnable)` them. Alternatively, you could use a Callable+Collection, because the Callable can return something other than null. – Jonathan Komar Aug 16 '19 at 05:46

score 20 · Answer 2 · answered Nov 02 '15 at 01:37

20

mHandler.removeCallbacks(updateThread);

answered Nov 02 '15 at 01:37

David Wang

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please, try to describe answer – Enamul Hassan Nov 02 '15 at 02:00
2

This is the easiest way for me. – bpiec Jan 10 '16 at 19:39
2

Actually, this seems to be the proper answer, as you don't have to create your own custom Runnable with all the yada-yada in it or use the ExecutorService. That's what the `removeCallbacks` method is there for. It's the closest to a JavaScript `clearTimeout`, same pattern. – Daniel F Jan 24 '17 at 03:10
28

This will only cancel pending runnables that have been posted to the thread queue. It will not stop the runnables which are already running. – GilCol Sep 27 '17 at 16:04

score 16 · Answer 3 · edited Dec 04 '12 at 12:14

public abstract class StoppableRunnable implements Runnable {

    private volatile boolean mIsStopped = false;

    public abstract void stoppableRun();

    public void run() {
        setStopped(false);
        while(!mIsStopped) {
            stoppableRun();
            stop();
        }
    }

    public boolean isStopped() {
        return mIsStopped;
    }

    private void setStopped(boolean isStop) {    
        if (mIsStopped != isStop)
            mIsStopped = isStop;
    }

    public void stop() {
        setStopped(true);
    }
}

class ......

    private Handler mHandler = new Handler();

public void onStopThread() {
    mTask.stop();       
    mHandler.removeCallbacks(mTask);
}

public void onStartThread(long delayMillis) {
    mHandler.postDelayed(mTask, delayMillis);
}

private StoppableRunnable mTask = new StoppableRunnable() {
    public void stoppableRun() {        
                    .....
            onStartThread(1000);                
        }
    }
};

Do you realize this implementation leaves your Runnable burning up CPU cycles? — stephen, Sep 07 '13 at 06:22

score 3 · Answer 4 · answered Feb 26 '12 at 23:00

3

changeColor is declared as Runnable, which does not have a kill() method.

You need to create your own interface that extends Runnable and adds a (public) kill() method.

answered Feb 26 '12 at 23:00

SLaks

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If I create a new class then the compiler says there is problem with "color_changer.postDelayed(changeColor, 150);" - changeColor cannot be resolved to variable. – c0dehunter Feb 26 '12 at 23:09
No; I mean interface. However, making a non-anonymous class would also work. Do you mean `this`? – SLaks Feb 26 '12 at 23:12
What exactly do you mean by Non Anonymous class @SLaks – Cyph3rCod3r Mar 13 '14 at 05:56
@Dr.aNdRO: I mean a regular named class, as opposed to an anonymous class. – SLaks Mar 13 '14 at 13:39

score -1 · Answer 5 · answered Sep 21 '19 at 07:55

You can Use this way

Stop Runnable Thread //==============================================================================

 ThreadUtil.startTask(() -> {
                        // doTask
                    }, 1500);


//==============================================================================
 public class ThreadUtil {

        private static Handler handler;
        private static Runnable runnable;

        public static void startTask(IThreadTask iThreadTask, long delayTime) {
            stopTask();
            handler = new Handler();
            runnable = () -> {
                iThreadTask.doTask();
            };

            if (handler == null || runnable == null) {
                return;
            }

            handler.postDelayed(runnable, delayTime);

        }

        public static void stopTask() {
            try {
                handler.removeCallbacks(runnable);
                handler.removeCallbacksAndMessages(null);
                handler = null;
                runnable = null;

            }catch (Exception e){
                Log.e("ThreadUtil:","Error:"+e.toString());

            }

        }


        public interface IThreadTask {
            void doTask();
        }


    }

Android: How do I stop Runnable?

5 Answers5

You can Use this way

Linked

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