runOnUiThread how to close/shutdown thread

Question

Q. I am using the code below to carry out a task which it is doing, however when the app ends I get an error which basically says the thread below was not shut down properly. Does anyone know how to close down this kind of thread.

private Handler aHandler = new Handler();
private final Runnable r = new Runnable()
{
    @Override
    public void run()
    {
        updateProgress();
    }
}; 

private void updateProgress()
{
    if (scrubber != null)
        Log.d("TAG", ...);

    aHandler.postDelayed(r, 1000);
}

// IN THE ON CREATE METHOD I USE

runOnUiThread(new Runnable()
{
    public void run()
    {
        updateProgress();
    }
});

Thankyou for your help but I am still getting error as can be seen below:

10-01 14:26:29.978: I/SurfaceView(19852): updateWindow -- OnPreDrawListener, mHaveFrame = true
10-01 14:26:29.978: D/dalvikvm(19852): threadid=15: interp stack at 0x60be9000
10-01 14:26:29.979: D/AndroidRuntime(19852): Shutting down VM
10-01 14:26:29.979: W/dalvikvm(19852): threadid=1: thread exiting with uncaught exception      (group=0x41f76c98)
10-01 14:26:29.979: W/dalvikvm(19852): threadid=1: uncaught exception occurred
10-01 14:26:29.979: W/System.err(19852): java.lang.IllegalStateException
10-01 14:26:29.980: W/System.err(19852):    at android.media.MediaPlayer.isPlaying(Native Method)
10-01 14:26:29.980: W/System.err(19852):    at com.aviit.bluebox.MediaActivity.updateProgress(MediaActivity.java:162)
10-01 14:26:29.980: W/System.err(19852):    at com.aviit.bluebox.MediaActivity.access$0(MediaActivity.java:157)
10-01 14:26:29.980: W/System.err(19852):    at com.aviit.bluebox.MediaActivity$1.run(MediaActivity.java:153)
10-01 14:26:29.980: W/System.err(19852):    at android.os.Handler.handleCallback(Handler.java:808)
10-01 14:26:29.980: W/System.err(19852):    at android.os.Handler.dispatchMessage(Handler.java:103)
10-01 14:26:29.980: W/System.err(19852):    at android.os.Looper.loop(Looper.java:193)
10-01 14:26:29.980: W/System.err(19852):    at android.app.ActivityThread.main(ActivityThread.java:5292)
10-01 14:26:29.981: W/System.err(19852):    at java.lang.reflect.Method.invokeNative(Native Method)
10-01 14:26:29.981: W/System.err(19852):    at java.lang.reflect.Method.invoke(Method.java:515)
10-01 14:26:29.981: W/System.err(19852):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
10-01 14:26:29.981: W/System.err(19852):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
10-01 14:26:29.981: W/System.err(19852):    at dalvik.system.NativeStart.main(Native Method)
10-01 14:26:29.981: W/dalvikvm(19852): threadid=1: calling UncaughtExceptionHandler
10-01 14:26:29.982: E/AndroidRuntime(19852): FATAL EXCEPTION: main
10-01 14:26:29.982: E/AndroidRuntime(19852): Process: com.aviit.bluebox, PID: 19852
10-01 14:26:29.982: E/AndroidRuntime(19852): java.lang.IllegalStateException
10-01 14:26:29.982: E/AndroidRuntime(19852):    at android.media.MediaPlayer.isPlaying(Native Method)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at com.aviit.bluebox.MediaActivity.updateProgress(MediaActivity.java:162)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at com.aviit.bluebox.MediaActivity.access$0(MediaActivity.java:157)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at com.aviit.bluebox.MediaActivity$1.run(MediaActivity.java:153)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at android.os.Handler.handleCallback(Handler.java:808)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at android.os.Handler.dispatchMessage(Handler.java:103)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at android.os.Looper.loop(Looper.java:193)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at android.app.ActivityThread.main(ActivityThread.java:5292)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at java.lang.reflect.Method.invokeNative(Native Method)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at java.lang.reflect.Method.invoke(Method.java:515)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
10-01 14:26:29.982: E/AndroidRuntime(19852):    at dalvik.system.NativeStart.main(Native Method)
10-01 14:27:02.097: D/dalvikvm(19852): threadid=12: exiting
10-01 14:27:02.097: D/dalvikvm(19852): threadid=12: bye!

Answer 1

private Handler aHandler = new Handler();
private final Runnable r = new Runnable()
{
    @Override
    public void run()
    {

        if (scrubber != null)
            Log.d("TAG", ...);

        aHandler.postDelayed(this, 1000);
    }
}; 

add somewhere in the code:

  aHandler.post(r); 

when it is done, you need to:

  aHandler.removeCallback(r);

Answer 2

If you want to finish this handler with clicking back button add this:

@Override
public void onBackPressed() {
   // stop Handler
   aHandler.removeCallbacks(r);
   // to stop anonymous runnable use aHandler.removeCallbacksAndMessages(null);
}

Or maybe you can solve that with adding this on your activities onDestroy() method:

@Override
protected void onDestroy() {
    // stop Handler
    aHandler.removeCallbacks(r);
    // to stop anonymous runnable use aHandler.removeCallbacksAndMessages(null);
    super.onDestroy();   
}