如何获取此地图代码的当前位置？当我打开地图时，还试图从服务器接收车辆数据

package com.androidhive.googlemaps;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.graphics.drawable.Drawable;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.LocationSource.OnLocationChangedListener;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;

public class AndroidGoogleMapsActivity extends MapActivity {


private Button login;
private EditText username, password;
private GoogleMap mMap;
private OnLocationChangedListener mListener;
private LocationManager locationManager;

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


    // Displaying Zooming controls
    MapView mapView = (MapView) findViewById(R.id.mapView);
    mapView.setBuiltInZoomControls(true);

    /**
     * Changing Map Type
     * */
     mapView.setSatellite(true); // Satellite View
     mapView.setStreetView(true); // Street View
     mapView.setTraffic(true); // Traffic view


    /**
     * showing location by Latitude and Longitude
     * */        
    MapController mc = mapView.getController();
    double lat = Double.parseDouble("48.85827758964043");
    double lon = Double.parseDouble("2.294543981552124");
    GeoPoint geoPoint = new GeoPoint((int)(lat * 1E6), (int)(lon * 1E6));
    mc.animateTo(geoPoint);
    mc.setZoom(15);
    mapView.invalidate(); 


    /**
     * Placing Marker
     * */
    List<Overlay> mapOverlays = mapView.getOverlays();
    Drawable drawable = this.getResources().getDrawable(R.drawable.mark_red);
    AddItemizedOverlay itemizedOverlay = 
         new AddItemizedOverlay(drawable, this);


    OverlayItem overlayitem = new OverlayItem(geoPoint, "Hello", "Sample Overlay item");

    itemizedOverlay.addOverlay(overlayitem);
    mapOverlays.add(itemizedOverlay);

}



@Override
protected boolean isRouteDisplayed() {
    return false;
}
package com.androidhive.googlemaps;

import jav