android obtains location data and gps latitude and longitude through gps

package com.action.android_test;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;
public class MainActivity extends Activity {
private Location location=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//获得位置服务的名称
String serviceName = this.LOCATION_SERVICE;
//获得位置服务的管理对象
LocationManager locationManager = (LocationManager)getSystemService(serviceName);
// 通过GPS获取定位的位置数据
location = locationManager.getLastKnownLocation(locationManager.GPS_PROVIDER);
updateToNewLocation(location);
    /**服务管理对象的监听器*/
    //参数1：定位的方式   参数2：监听更新间隔时间(ms)  参数3：监听更新的距离(m) 参数4：监听的方法
    locationManager.requestLocationUpdates(locationManager.GPS_PROVIDER, 2000, 10, new LocationListener() {
        public void onStatusChanged(String provider, int status, Bundle extras) {
        }
        public void onProviderEnabled(String provider) {
        }
        public void onProviderDisabled(String provider) {
        }
        public void onLocationChanged(Location location) {
            updateToNewLocation(location);
        }
    });
}
private void updateToNewLocation(Location location) {
    TextView tv1;
    tv1 = (TextView) this.findViewById(R.id.tv1);
    if (location != null) {
        double  latitude = location.getLatitude();
        double longitude= location.getLongitude();
        tv1.setText("经纬度为：n"+"维度：" +  latitude+ "n经度" + longitude);
    } else {
        tv1.setText("无法获取地理信息");
    }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}