Android service isn't killing background process, nor does stopSelf() work

Question

I want to close Whatsapp, if it is every opened by the user. By close, I mean to completely kill it from the background. The service class should be able to run for 30 seconds. My code is as follows:

serviceclass_code:

public class Timer extends Service {
    long time=30000; //30 seconds
    Notification n;
    long current_time=0;
    String app="Whatsapp";

    public Timer() {
    }

    @Override
    public void onCreate() {
        current_time=System.currentTimeMillis();
        n = new NotificationCompat.Builder(this,CHANNEL_ID)
                .setContentTitle("Timer")
                .setContentText("You can use "+app+" only for "+time+" seconds")
                .setSmallIcon(R.drawable.ic_launcher_foreground)
                .build();
        startForeground(1,n);
        super.onCreate();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);

        am.killBackgroundProcesses("com.whatsapp");  //package name of 'Whatsapp`
       
        if((System.currentTimeMillis() - current_time)==time){
            stopForeground(Service.STOP_FOREGROUND_REMOVE); //should remove notification
            stopSelf(); //should stop service
        }

        return START_STICKY;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        throw new UnsupportedOperationException("Not yet implemented");
    }
}

But when I execute the code, neither does the service class kill the Whatsapp process, nor does the notification get dismissed after 30 seconds is over. The service keeps on running forever, and Whatsapp is still running in the background. Why?

Answer 1

Possible reasons:

1. Service has not unbind: After binding the service in onCreate() it need to unbind it in onDestroy()method

2. Memory leak: If you are using worker threads that have not finished when the stopSelf is called. You can use the below to stop a service: 


   android.os.Process.killProcess(android.os.Process.Pid()); 


   But, first, clean up the worked thread before executing the above, else you may leak memory.

3. Do the cleanup task in onDestroy() method of the service if required (Unregistered or disconnect any API or reset any condition, etc)

4. If you are using a foreground service then use stopForeground(true) inserted of stopSelf() (as it is meant to be used for normal services).