How to get location either from GPS or NETWORK providers in android

Question

In my android app I'm retrieving user location for every 3 minutes and somehow I'm doing it in the following way.problems so far I have faced are

1. Whenever I'm getting location updates I'm getting multiple values at same time
2. Sometimes I'm getting both GPS and NETWORK provider values at a time.

I need only one value and also it should be either GPS or NETWORK Provider value,How to achieve this.

Here is my Service

public class MyService extends Service {
private static final String TAG = "TESTGPS";
private LocationManager mLocationManager = null;
private static final int LOCATION_INTERVAL = 180000;
private static final float LOCATION_DISTANCE = 0.0f;
double lati,longi;
String loc_name;

private class LocationListener implements android.location.LocationListener {
    Location mLastLocation;


    public LocationListener(String provider) {
        Log.i(TAG, "LocationListener " + provider);
        mLastLocation = new Location(provider);
    }

    @Override
    public void onLocationChanged(Location location) {
        Log.i(TAG, "onLocationChanged: " + location);
        Toast.makeText(getApplicationContext(), ""+location.getLatitude()+"==>"+location.getLongitude(), Toast.LENGTH_SHORT).show();

        lati = location.getLatitude();
        longi = location.getLongitude();

        Geocoder geocoder = new Geocoder(getApplicationContext(), Locale.getDefault());
        try {
            List<Address> addressList = geocoder.getFromLocation(
                    lati, longi, 1);
            if (addressList != null && addressList.size() > 0) {
                {
                    loc_name = addressList.get(0).getAddressLine(1);

                }
                AsyncHttpClient client = new AsyncHttpClient();
                final RequestParams params = new RequestParams();
                params.put("sendingJSON", composeLocation());
                Toast.makeText(getApplicationContext(), "" + params, Toast.LENGTH_LONG).show();
                client.post("http://192.168.0.120/gpstracker/send_location.php", params, new AsyncHttpResponseHandler() {

                    public void onSuccess(String response) {

                        Log.i("Status ==> ", "Sent to server");

                    }

                    public void onFailure(int statusCode, Throwable error, String content) {
                        if (statusCode == 404) {

                            Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
                        } else if (statusCode == 500) {

                            Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
                        } else {

                            Toast.makeText(getApplicationContext(), "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet]", Toast.LENGTH_LONG).show();
                        }
                    }

                });

            }
        } catch (IOException e) {
            e.printStackTrace();

            mLastLocation.set(location);
        }
    }

    @Override
    public void onProviderDisabled(String provider) {
        Log.i(TAG, "onProviderDisabled: " + provider);
    }

    @Override
    public void onProviderEnabled(String provider) {
        Log.i(TAG, "onProviderEnabled: " + provider);
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        Log.i(TAG, "onStatusChanged: " + provider);
    }
}

LocationListener[] mLocationListeners = new LocationListener[]{
        new LocationListener(LocationManager.GPS_PROVIDER),
        new LocationListener(LocationManager.NETWORK_PROVIDER)
};

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

public int onStartCommand(Intent intent, int flags, int startId) {
    //Toast.makeText(MyService.this, "Service Started", Toast.LENGTH_SHORT).show();

    Log.i("Service Started", "Started");
    return START_STICKY;

}

@Override
public void onCreate() {
    Log.e(TAG, "onCreate");
    initializeLocationManager();
    try {
        mLocationManager.requestLocationUpdates(
                LocationManager.NETWORK_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
                mLocationListeners[1]);
    } catch (java.lang.SecurityException ex) {
        Log.i(TAG, "fail to request location update, ignore", ex);
    } catch (IllegalArgumentException ex) {
        Log.d(TAG, "network provider does not exist, " + ex.getMessage());
    }
    try {
        mLocationManager.requestLocationUpdates(
                LocationManager.GPS_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
                mLocationListeners[0]);
    } catch (java.lang.SecurityException ex) {
        Log.i(TAG, "fail to request location update, ignore", ex);
    } catch (IllegalArgumentException ex) {
        Log.d(TAG, "gps provider does not exist " + ex.getMessage());
    }
}

@Override
public void onDestroy() {
    Log.e(TAG, "onDestroy");
    super.onDestroy();
    if (mLocationManager != null) {
        for (int i = 0; i < mLocationListeners.length; i++) {
            try {
                if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    // TODO: Consider calling
                    //    ActivityCompat#requestPermissions
                    // here to request the missing permissions, and then overriding
                    //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                    //                                          int[] grantResults)
                    // to handle the case where the user grants the permission. See the documentation
                    // for ActivityCompat#requestPermissions for more details.
                    return;
                }
                mLocationManager.removeUpdates(mLocationListeners[i]);
            } catch (Exception ex) {
                Log.i(TAG, "fail to remove location listners, ignore", ex);
            }
        }
    }
}
private void initializeLocationManager() {
    Log.i(TAG, "initializeLocationManager");
    if (mLocationManager == null) {
        mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);

    }
}

public String composeLocation()
{
    ArrayList<HashMap<String, String>> locationList = new ArrayList();
    HashMap<String, String> map = new HashMap();
    String parsed_lati = String.valueOf(lati);
    String parsed_longi = String.valueOf(longi);
    map.put("e1", "123");
    map.put("lati",parsed_lati);
    map.put("longi",parsed_longi);
    map.put("loc_name",loc_name);
    locationList.add(map);
    return new GsonBuilder().create().toJson(locationList);
}


}

Answer 1

You should use Criteria to request location update instead of using Provider:

    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_COARSE);
    locationManager.requestSingleUpdate(criteria, listener, null);

That way you can use only one listener and the location value can be from either GPS or NETWORK provider.

Answer 2

You should first check before getting location from both. First check if location is available through gps and if not then use network to get location. Here is a sample class which have methods for checking location.

    public class GPSTracker extends Service implements LocationListener {

    private final Context context;

    boolean isGPSEnabled = false;
    boolean isNetworkEnabled = false;
    public boolean canGetLocation = false;

    Location location;

    double latitude;
    double longitude;

    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1;

    protected LocationManager locationManager;

    public GPSTracker(Context context) {
        this.context = context;
        getLocation();
    }

    public Location getLocation() {
        try {
            locationManager = (LocationManager) context.getSystemService(LOCATION_SERVICE);

            isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

            isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if(!isGPSEnabled && !isNetworkEnabled) {

            } else {
                this.canGetLocation = true;

                if (isNetworkEnabled) {

                    locationManager.requestLocationUpdates(
                            LocationManager.NETWORK_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);

                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

                        if (location != null) {

                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }

                }

                if(isGPSEnabled) {
                    if(location == null) {
                        locationManager.requestLocationUpdates(
                                LocationManager.GPS_PROVIDER,
                                MIN_TIME_BW_UPDATES,
                                MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                        if(locationManager != null) {
                            location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

                            if(location != null) {
                                latitude = location.getLatitude();
                                longitude = location.getLongitude();
                            }
                        }
                    }
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return location;
    }


    public void stopUsingGPS() {
        if(locationManager != null) {
            locationManager.removeUpdates(GPSTracker.this);
        }
    }

    public double getLatitude() {
        if(location != null) {
            latitude = location.getLatitude();
        }
        return latitude;
    }

    public double getLongitude() {
        if(location != null) {
            longitude = location.getLongitude();
        }

        return longitude;
    }

    public boolean canGetLocation() {
        return this.canGetLocation;
    }

    public void showSettingsAlert() {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);

        alertDialog.setTitle("GPS is settings");

        alertDialog.setMessage("Turn on your GPS to find nearby helpers");

        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                context.startActivity(intent);
            }
        });

        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });

        alertDialog.show();
    }

    @Override
    public void onLocationChanged(Location arg0) {
        // TODO Auto-generated method stub

    }

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

    }

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

    }

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

    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }

}