using asynTask to update LocationListener

Question

im already looking for the aswer in this forum but none working, im creating an android apps and im trying to get coordinate update from locationlistener in asyncTask (my asyncTask job only to update the latitute and longitude) while the main thread get the coodinate from the asyncTask via Location Manager, and it works yesterday, today its not working anymore, here's my asyncTask code :

 private class LoopMsg extends AsyncTask<String,Void,Void>{
        protected Void doInBackground(String... urls){

            Looper.prepare();

            LocationListener listen = new LocationListener() {

                @Override
                public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
                    // TODO Auto-generated method stub

                }

                @Override
                public void onProviderEnabled(String arg0) {
                    // TODO Auto-generated method stub

                }

                @Override
                public void onProviderDisabled(String arg0) {
                    // TODO Auto-generated method stub

                }

                @Override
                public void onLocationChanged(Location loc) {
                    // TODO Auto-generated method stub

                    Log.d(TAG,"Latitude :"+String.valueOf(loc.getLatitude()));
                    Log.d(TAG,"Longitude :"+String.valueOf(loc.getLongitude()));
                    Glatitude = loc.getLatitude();
                    Glongitude = loc.getLongitude();
                }
            };          
            lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 60000, 0, listen);
            Looper.loop();


            return null;

        }
    }

please help me what went wrong here? and how to fix this? it running good before the next day i got exception at Looper.prepare() it says that only one looper may be created per thread, then i delete Looper.prepare and Looper.loop Part, the error change become

*FATAL EXCEPTION: asyncTask #1
*java.lang.RuntimeException: an error occured while executing do in background

im really don't know why, coz im not update ui thread at my doInBackground method

why i know my app not working : 1.onLocationChanged never called again 2.the app crash if im not using looper.prepare and looper.loop

and I also tried like this :

lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 60000, 0, listen, Looper.getMainLooper());

and this :

Looper.Mylooper.prepare();
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 60000, 0, listen, Looper.getMyLooper());

but still no luck,the app still not running

this is the logCat i got after removing the Looper in AsyncTask (and the app always crash)

-Fatal Exception: AsyncTask#2
-java.lang.RuntimeException: An error occured while executing doInBackground()
-at android.os.AsyncTask$3.done(AsyncTask.java:299)
-at java.util.concurrent.FutureTask.finishCompletion(FutureTask.Java:219)
-at java.util.concurrent.FutureTask.run(FutureTask.Java:239)
-at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
-at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
-at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
-at java.lang.Thread.run(Thread.java:838)
-Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not  called Looper.prepare()
-at android.os.Handler.<init>(Handler.java:197)
-at android.os.Handler.<init>(Handler.java:111)
-at android.location.LocationManager$ListenerTransport$1.<init>(LocationManager.java:199)
-at android.location.LocationManager$ListenerTransport.<init>(LocationManager.java:199)
-at android.location.LocationManager.wrapListener(LocationManager.java:822)
-at android.location.LocationManager.requestLocationUpdates(LocationManager.java:835)
-at android.location.LocationManager.requestLocationUpdates(LocationManager.java:432)
-at android.location.ZTEPrivacyLocationManager.requestLocationUpdates(ZTEPrivacyLocationManager.java:107)
-at com.login.absen.MyService$LoopMsg.doInBackground(MyService.java:244)
-at com.login.absen.MyService$LoopMsg.doInBackground(MyService.java:1)
-at android.os.AsyncTask$2.call(AsyncTask.java:287)
-at java.util.concurrent.FutureTask.run(FutureTask.java:234)
-... 4 more

UPDATE

i guest i can simplyfy the problem Actually the problem was the onLocationChange method not called at (zte n986 - android 4.2) , im trying this code in another device (journey - android 2.3.3) the behavior was the same, asyncTask also stop running at Looper.loop BUT the onLocationChange method was running, so the location update still running

Answer 1

First there is no need of AsyncTask for listening for location update. LocationLintener itself run asynchronously so just register for location update and update the ui in

 public void onLocationChanged(Location loc) {
                    // TODO Auto-generated method stub


                }

Answer 2

Use Service and you can use Location Listner there,no ne

Answer 3

public class LocateDeviceService extends Service {

private static final String TAG = "";

double lat = 0;
    double lng = 0;



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

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    customHandler.postDelayed(updateTimerThread, 0);
    return super.onStartCommand(intent, flags, startId);
}

private Handler customHandler = new Handler();

private Runnable updateTimerThread = new Runnable() {

    public void run() {
        try {
            //send location

    LocationManager locman = (LocationManager) context
            .getSystemService(Context.LOCATION_SERVICE);

    Criteria criteria = new Criteria();
    String provider = locman.getBestProvider(criteria, false);
    Location location = locman.getLastKnownLocation(provider);

    if (location != null) {
        lat = location.getLatitude();
        lng = location.getLongitude();

    }

            customHandler.postDelayed(this,60000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }

};



public void sendLocationToServer(Double lat,Double lng )
        throws InterruptedException {
    //do ur job here

}

@Override
public void onDestroy() {
    // TODO Auto-generated method stub
    super.onDestroy();
    if (null != customHandler && null != updateTimerThread) {
        customHandler.removeCallbacks(updateTimerThread);
    }
}
}

Answer 4

There is no need for AsyncTask to get location changes. Locations can be sent to your registered class running on main thread. If you want to upload the location to a server, then use AsynTask only for that portion.

Here are steps:
1. Implement "LocationListener" on your class that extends Service.
2. Then you need to implement the unimplemented methods in the LocationListener. Location is passed to you on is:

    @Override
    public void onLocationChanged(Location location) {
        //Use AsyncTask only to upload the location information
        uploadLocationToServerThroughAsyncTask(location);   
    }

3. Now, register with LocationManager to send the locations to your class when it changes as below:

    lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_COARSE);
    String provider = lm.getBestProvider(criteria, true);
    if (provider == null || provider.trim().isEmpty()) {
        // No provider hence return.
        return;
        }
    // If there are any available provider, then register for location updates.
    lm.requestLocationUpdates(locProvider, 1000, 200, this); // 1 sec and 200 meter updates 

4. Unregister from location manager at the appropriate time as below:

    try {
        lm.removeUpdates(this);
        } catch (Exception e) {
        e.printStackTrace();
    }