Android: Service restarts after app gets started

Question

Im trying to achive, that my service downloads information and fills a database with that information in the background.

SOLUTION (Using foreground service, code is now the edited-version)

Thats the service:

public class UnitPullService extends Service {
    private final static String name = UnitPullService.class.getSimpleName();
    public static Boolean isRunning = false;
    private Looper mServiceLooper;
    private ServiceHandler mServiceHandler;

    private final class ServiceHandler extends Handler {
        public ServiceHandler(Looper looper) {
            super(looper);
        }

        @Override
        public void handleMessage(Message msg) {
            try {
                UnitDataSource unitdataSource = new UnitDataSource(getApplicationContext());
                unitdataSource.fillTables();
                SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
                SharedPreferences.Editor spEitor = sharedPreferences.edit();
                // disables the button which starts this service
                spEitor.putBoolean("isFilled", true);
                spEitor.commit();
            } catch (JSONException e) {
                e.printStackTrace();
            }
            stopSelf(msg.arg1);
        }
    }

    @Override
    public void onCreate() {
        HandlerThread thread = new HandlerThread("ServiceStartArguments",
            Process.THREAD_PRIORITY_BACKGROUND);
        thread.start();

        mServiceLooper = thread.getLooper();
        mServiceHandler = new ServiceHandler(mServiceLooper);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // PART OF THE SOLUTION
        startForeground(1000, new Notification());

        Toast.makeText(this, "service starting", 
           Toast.LENGTH_SHORT).show();
        // to check if the service is currently running
        isRunning = true;
        Message msg = mServiceHandler.obtainMessage();
        msg.arg1 = startId;
        mServiceHandler.sendMessage(msg);

        return START_REDELIVER_INTENT;
    }

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

    @Override
    public void onDestroy() {
        Toast.makeText(this, "service done", Toast.LENGTH_SHORT).show();
    }
}

And thats the intent in the activity (actually from a fragment):

 Intent i= new Intent(getContext(), UnitPullService.class);
 getContext().startService(i);

In the manifest, the service is declared like:

<service
  android:name=".UnitPullService"
  android:exported="false"/>

The point is, that i want to do the whole "download and database filling"-stuff completly independent from the status of the app which is starting the service (so that the user can use other apps while the service is doing its job).

EDIT (Made false assumptions)

The following behaves weird:

1. Start application
2. Start service
3. Close application (swipe away from running-apps-overview)
4. Start application before service has finished
5. "service starting"-toast shows up, handleMessage() gets called and DatabaseErros happening (because of unique constrains, but thats not the point).

the other scenario:

1. Start application
2. Start service
3. Close application (swipe away from running-apps-overview)
4. fillTables() has finished.
5. It seems that directly after fillTables() has finished and the service gets restarted (Toast shows up).

Q1: So where is my fault, that the running service is going to restart when I start the application while a running service has not finished yet?

Q1.1: How do i call/create a completly independent service, which does not get restarted in such an anoying way, while doing its job?

Answer 1

Swiping away the app puts it in Force-close state. That kills any services attached to it. It won't allow the service or any other activity in the app to run again until the user has launched it.

Now if the user doesn't swipe away, your service will continue to run no matter what app is in the foreground. And if the service is killed by the OS for resources, you can have it automatically restart when they're available. But nothing will make it run services after being swiped away.