Question

I’m following the book ‘Beginning Android 4 Development’, and I’m controlling a service using the following functions from buttons:

public void startService(View view) {
    startService(new Intent(getBaseContext(), QOLService.class));
}

public void stopService(View view) {
    stopService(new Intent(getBaseContext(), QOLService.class));
}

QOLService.java includes

public class QOLService extends Service {

    int counter = 0;

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        //Keep running service until stopped, so return sticky
        Timer timer=new Timer();
        TimerTask tt =new TimerTask() {
            @Override
            public void run() {
                Log.d("QOLService", String.valueOf(++counter));
                }
        };

        timer.scheduleAtFixedRate(tt, 0, 1000);

        Toast.makeText(this, "Service started", Toast.LENGTH_LONG).show();
        return START_STICKY;
    }


    @Override
    public void onDestroy() {
        super.onDestroy();
        Toast.makeText(this, "Service destroyed", Toast.LENGTH_LONG).show();
    }

As intended, on pressing the start button I get the ‘service started’ toast, and in logcat I get a message incrementing every second. This continues, as intended, even when the application is closed.

When I click the stopservice button, I also get the expected ‘service destroyed’ message, but the timer lives on! If I close the application it still keeps going. If I click the stopservice button again, it does NOT given the service destroyed message, as if it had been successfully destroyed the first time.

Am I calling my timer inappropriately? If so, I seem to be doing it exactly as the book advises!

Answer 1

I am agree with CommonsWare, You haven’t stop your timer in the code. I suggest you to go this way,

public class QOLService extends Service {

    int counter = 0;
    Timer timer;
    TimerTask tt;

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        //Keep running service until stopped, so return sticky
        timer=new Timer();
        tt =new TimerTask() {
            @Override
            public void run() {
                Log.d("QOLService", String.valueOf(++counter));
                }
        };

        timer.scheduleAtFixedRate(tt, 0, 1000);

        Toast.makeText(this, "Service started", Toast.LENGTH_LONG).show();
        return START_STICKY;
    }


    @Override
    public void onDestroy() {
        super.onDestroy();
        Toast.makeText(this, "Service destroyed", Toast.LENGTH_LONG).show();
        tt.cancel();
        timer.cancel();
    }
}

The cancel() method will stop your Timer as well as.