Running process also if the app is closed

Question

i'm making an app that needs to check if a file exist every, let's say, 10 seconds. And then send a message if there's written "SEND" in the file, otherwise do nothing. How could i create a thread/process that will check every 10 seconds if there's the file, even if i close the app? Is it possible? This is my code:

public class BootListener extends BroadcastReceiver {
    public BootListener() {
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        context.startService(new Intent(context, FileCheckerService.class));
    }
}


public class FileCheckerService extends Service {
    public FileCheckerService() {
    }

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

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        TimerTask task = new TimerTask() {
            @Override
            public void run() {
                SmsManager newSms = SmsManager.getDefault();
                newSms.sendTextMessage(
                        "+39334659348",
                        null,
                        "TRY",
                        null,
                        null);
            }
        };

        Timer timer = new Timer();
        timer.schedule(task, 0, 20000);

        return START_STICKY;
    }

    public static String convertStreamToString(InputStream is) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) {
            sb.append(line).append("\n");
        }
        reader.close();
        return sb.toString();
    }
}

Answer 1

Try using a service. read more about correct way of using a service:

http://developer.android.com/reference/android/app/Service.html

Answer 2

Create a service with application context with overding startCommand returning Service.start_sticky flag and have thread in side in which set while loop like below

while(true)
 {
    yourThreadReference.sleep(10000); // this is 10 seconds
    // do your work  
 }