I was following a tutorial and trying to get my current location using Google maps but I am getting an error at LatLng, it says that 'attempt to invoke virtual method and a null object reference'. I want to get my current location and also get latitude and longitude as strings. I am wanna use these latitude and longitude for live location tracking.
public class DriverCurrentLocationActivity extends FragmentActivity implements OnMapReadyCallback {
    private GoogleMap mMap;
    LocationManager locationManager;
    LocationListener locationListener;
    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == 1) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
                    Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                    updateMap(lastKnownLocation);
                }
            }
        }
    }
    public void updateMap(Location location) {
        try {
            LatLng userLocation = new LatLng(location.getLatitude(), location.getLongitude());
            mMap.clear();
            mMap.moveCamera(CameraUpdateFactory.newLatLng(userLocation));
            mMap.addMarker(new MarkerOptions().position(userLocation).title("Your Location"));
        }catch (Exception e){
            Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
        }
        }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_driver_current_location);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                updateMap(location);
            }
            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {
            }
            @Override
            public void onProviderEnabled(String provider) {
            }
            @Override
            public void onProviderDisabled(String provider) {
            }
        };
        if (Build.VERSION.SDK_INT < 23) {
            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
        }else {
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED){
                ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.ACCESS_FINE_LOCATION},1);
            } else {
                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener);
                Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                if (lastKnownLocation != null){
                    updateMap(lastKnownLocation);
                }
            }
        }
    }
} 
     
    