Sometimes I am getting empty location until I restart my phone why?

view story

http://stackoverflow.com – So I am getting the longitude and latitude as: locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); // Define a listener that responds to location updates locationListener = new LocationListener() { public void onLocationChanged(Location location) { // Called when a new location is found by the network location provider. longitude=location.getLongitude(); latitude=location.getLatitude(); } public void onStatusChanged(String provider, int status, Bundle extr (HowTos)