public class MainActivity extends MapActivity { 
 private MapView mapView;
 private MapController mapController; 
 private LocationManager  mlocationManager;
 private Location  myLocation;
 private MyLocationOverlay myLocationOverlay;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);       
        mapView = (MapView)findViewById(R.id.mapView);
        mapView.setSatellite(true);
        mapView.setStreetView(true);
        mapView.setTraffic(true);
        mapView.setBuiltInZoomControls(true);
       myLocationOverlay = new MyLocationOverlay ( this, mapView );
 myLocationOverlay.enableMyLocation();
 mapController.setZoom(16);
 mlocationManager= (LocationManager)getSystemService( Context.LOCATION_SERVICE );
 Criteria criteria = new Criteria();
 criteria.setAltitudeRequired( false );
 criteria.setBearingRequired( false );
 criteria.setCostAllowed( true );
 criteria.setPowerRequirement( Criteria.POWER_LOW );
 criteria.setAccuracy( Criteria.NO_REQUIREMENT );
 String provider = mlocationManager.getBestProvider( criteria, true );
 myLocation = mlocationManager.getLastKnownLocation( provider );
 updateLocation (myLocation);
 mlocationManager.requestLocationUpdates( provider, 500, 5, locationListener );
}
    private final LocationListener locationListener = new LocationListener()
    {   
     public void onLocationChanged( Location location)
     {
      myLocation = location;
      updateLocation( location );
     }
     public void onProviderDisabled( String provider )
     {
     }
     public void onProviderEnabled( String provider )
     {
     } 
     public void onProviderChanged( String provider, int status, Bundle extras)
     {
     }
  public void onStatusChanged(String provider, int status, Bundle extras) { 
  }
    };
    @Override
    protected boolean isRouteDisplayed(){
     return false;
    }
    
    private void updateLocation( Location location )
    {
     if( location != null )
     {
      Double geoLatitude = location.getLatitude() * 1E6;
      Double geoLongitude = location.getLongitude() * 1E6;
      GeoPoint geoPoint =new GeoPoint( geoLatitude.intValue(), geoLongitude.intValue());
      mapController.animateTo( geoPoint );
      List<Overlay> listOfOverlays = mapView.getOverlays();
      listOfOverlays.clear();
      mapView.getOverlays().add( myLocationOverlay );
     }
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }    
}

안드로이드 한지 얼마 안되서 잘 몰라 질문 드림니다..

java.lang.NullPointerException 대한 것에 해결이 안되서 질문드림니다.