Android Location listener in Service does not work until I reactivate WiFi/mobile network

Question

My location listener works normally, collects data without any problem. But sometimes it doesn't collect any data. I have to turn off and restart my location provider at this time. Restarting fixes the problem,however, it's probably not the best thing the user is expected to do.

When I use GPS as provider, there is no problem.

Location listener works in Service. I can't understand the problem. Is it about Android or my code?

Thanks in advance.

Answer 1

Using the network provider requires internet connection to work. It collects some information from the cell and wifi hotspots. It then queries a backend server which looks up its database and gives an approximate location. The device can prefetch some location info so you don't need constant internet connection but when the device moves out of the prefetch location, it will need internet connection again.

This might be your problem that you loose internet connection sometime (wifi going to sleep) and restarting the provider gets it to reconnect to the internet again. Again this is at best a guess on my part :)

Answer 2

You could use new location provider (FusedLocationProvider), which combines info from different location providers, so if your device has any possibility to obtain location, You'll get know it. Of course, You should enable in preferences for your device to use location info by apps.

Check developers.android.com for extended info about this provider.

This is solution working fine for me:

public class FusedLocationListener implements GooglePlayServicesClient.ConnectionCallbacks, GooglePlayServicesClient.OnConnectionFailedListener, com.google.android.gms.location.LocationListener  {

    public interface LocationListener {
        public void onReceiveLocation(Location location);
    }

    private LocationListener mListener;

    public static final String TAG = "Fused";
    private LocationClient locationClient;
    private LocationRequest locationRequest;


    protected int minDistanceToUpdate = 1000;
    protected int minTimeToUpdate = 10*1000;

    protected Context mContext;


    @Override
    public void onConnected(Bundle bundle) {
        Log.d(TAG, "Connected");
        locationRequest = new LocationRequest();
        locationRequest.setSmallestDisplacement(1);
        locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        locationRequest.setInterval(30000);
        locationRequest.setNumUpdates(1);
        locationClient.requestLocationUpdates(locationRequest, this);

    }

    @Override
    public void onDisconnected() {
        Log.d(TAG, "Disconnected");
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        Log.d(TAG, "Failed");
    }


    private static FusedLocationListener instance;

    public static synchronized FusedLocationListener getInstance(Context context, LocationListener listener){
        if (null==instance) {
            instance = new FusedLocationListener(context, listener);
        }
        return instance;
    }


    private FusedLocationListener(Context context, LocationListener listener){
        mContext = context;
        mListener = listener;
    }


    public void start(){

        Log.d(TAG, "Listener started");
        locationClient = new LocationClient(mContext,this,this);
        locationClient.connect();

    }


    @Override
    public void onLocationChanged(Location location) {
        Log.d(TAG, "Location received: " + location.getLatitude() + ";" + location.getLongitude());
        //notify listener with new location
        mListener.onReceiveLocation(location);
    }


    public void stop() {
        locationClient.removeLocationUpdates(this);
    }
}

Usage:

public class MyActivity extends Activity implements FusedLocationListener.LocationListener {

 @Override
    public void onCreate(Bundle savedInstanceState) {

      FusedLocationListener locationListener FusedLocationListener.getInstance(getApplicationContext(), this);             

       locationListener.start();
   }

@Override
    public void onReceiveLocation(Location location) {
       //handle location here
    }

}

Answer 3

You can create detect both of these for me I've used both GPS_PROVIDER and NETWORK_PROVIDER if It can't detect any GPS after 20seconds it will try to use NETWORK provider

///First create MYlocation class

    public class MyLocation {
                Timer timer1;
                LocationManager lm;
                LocationResult locationResult;
                boolean gps_enabled=false;
                boolean network_enabled=false;

                public boolean getLocation(Context context, LocationResult result)
                {
                    //I use LocationResult callback class to pass location value from MyLocation to user code.
                    locationResult=result;
                    if(lm==null)
                        lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

                    //exceptions will be thrown if provider is not permitted.
                    try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
                    try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}

                    //don't start listeners if no provider is enabled
                    if(!gps_enabled && !network_enabled)
                        return false;

                    if(gps_enabled)
                        lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
                    if(network_enabled)
                        lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
                    timer1=new Timer();
                    timer1.schedule(new GetLastLocation(), 20000);
                    return true;
                }

                LocationListener locationListenerGps = new LocationListener() {
                    public void onLocationChanged(Location location) {
                        timer1.cancel();
                        locationResult.gotLocation(location);
                        lm.removeUpdates(this);
                        lm.removeUpdates(locationListenerNetwork);
                    }
                    public void onProviderDisabled(String provider) {}
                    public void onProviderEnabled(String provider) {}
                    public void onStatusChanged(String provider, int status, Bundle extras) {}
                };

                LocationListener locationListenerNetwork = new LocationListener() {
                    public void onLocationChanged(Location location) {
                        timer1.cancel();
                        locationResult.gotLocation(location);
                        lm.removeUpdates(this);
                        lm.removeUpdates(locationListenerGps);
                    }
                    public void onProviderDisabled(String provider) {}
                    public void onProviderEnabled(String provider) {}
                    public void onStatusChanged(String provider, int status, Bundle extras) {}
                };

                class GetLastLocation extends TimerTask {
                    @Override
                    public void run() {
                         lm.removeUpdates(locationListenerGps);
                         lm.removeUpdates(locationListenerNetwork);

                         Location net_loc=null, gps_loc=null;
                         if(gps_enabled)
                             gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                         if(network_enabled)
                             net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

                         //if there are both values use the latest one
                         if(gps_loc!=null && net_loc!=null){
                             if(gps_loc.getTime()>net_loc.getTime())
                                 locationResult.gotLocation(gps_loc);
                             else
                                 locationResult.gotLocation(net_loc);
                             return;
                         }

                         if(gps_loc!=null){
                             locationResult.gotLocation(gps_loc);
                             return;
                         }
                         if(net_loc!=null){
                             locationResult.gotLocation(net_loc);
                             return;
                         }
                         locationResult.gotLocation(null);
                    }
                }
                public void cancelTimer()
                { timer1.cancel(); 
                  lm.removeUpdates(locationListenerGps);
                  lm.removeUpdates(locationListenerNetwork);
                }
                public static abstract class LocationResult{
                    public abstract void gotLocation(Location location);
                }

        }

/Into your main class you can use it like this which I implies to a webview

   public class Main extends Activity {

     public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);


        mWebView=(WebView)findViewById(R.id.webview);


                final String string_loc = getIntent().getExtras().getString("nearest");
                LocationResult locationResult = new LocationResult(){

                    @Override
                    public void gotLocation(Location location) {

                        passLat=Double.toString(location.getLatitude());
                        passLong=Double.toString(location.getLongitude());
                        maps="http://maps.google.com/maps?q="+string_loc+"+loc:"+passLat+","+passLong+"&hq=hospital&t=m&z=12";
                        mWebView.loadUrl(maps);
                    }
                };
                  myLocation.getLocation(this, locationResult);  
        }

  }
}

//Hoping this would help you

Answer 4

Why dont you use both *GPS_PROVIDER* and *NETWORK_PROVIDER* ? I tried this and it was working fine.

Does this error occur while testing on other devices also or only your device ?