It is a problem of finding the current location (latitude, hardness) using Android gps.

    // Acquire a reference to the system Location Manager
    LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);

    // GPS provider availability
    isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
    // Network provider availability
    isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

    Log.d("Main", "isGPSEnabled=" + isGPSEnabled);
    Log.d("Main", "isNetworkEnabled=" + isNetworkEnabled);

    LocationListener locationListener = new LocationListener() {
        public void onLocationChanged(Location location) {
            double lat = location.getLatitude();
            double lng = location.getLongitude();
            Toast.makeText(BT_List.this, lat + " " + lng, Toast.LENGTH_SHORT).show();
        }

        public void onStatusChanged(String provider, int status, Bundle extras) {
        }

        public void onProviderEnabled(String provider) {
        }

        public void onProviderDisabled(String provider) {
        }
    };

    // // Register the listener with the Location Manager to receive location updates
    if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.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;
    }
    locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

    // Obtain Location Manually
    String locationProvider = LocationManager.GPS_PROVIDER;
    Location lastKnownLocation = locationManager.getLastKnownLocation(locationProvider);
    if (lastKnownLocation != null) {
        double lng = lastKnownLocation.getLatitude();
        double lat = lastKnownLocation.getLatitude();
        Log.d("Main", "longtitude=" + lng + ", latitude=" + lat);
    }