安卓程序无法获取位置信息的问题

package com.example.location03;



import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;



import org.apache.http.HttpEntity;

import org.apache.http.HttpResponse;

import org.apache.http.client.ClientProtocolException;

import org.apache.http.client.HttpClient;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.impl.client.DefaultHttpClient;



import android.app.Activity;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

//import android.content.DialogInterface;

//import android.content.DialogInterface.OnClickListener;



public class MainActivity extends Activity {



	private Button geocoding = null;

	private Button reverseGeocoding = null;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        geocoding = (Button)findViewById(R.id.geocoding);

        geocoding.setOnClickListener(new OnClickListener(){



		@Override

		public void onClick(View arg0) {

				

			new Thread(){

					public void run(){

					Log.d("yinan", "run");/////////

					String url = "http://maps.google.com/maps/api/geocode/json?address=SFO&sensor=false";

					String responseData = "" ;

					Log.d("yinan", "url");/////////

					HttpClient httpClient = new DefaultHttpClient();

					Log.d("yinan", "DefaultHttpClient");/////////

						try {

							Log.d("yinan", "#############");/////////

							HttpResponse httpResponse = httpClient.execute(new HttpGet(url));

							Log.d("yinan", "httpResponse");/////////

							HttpEntity entity = httpResponse.getEntity();

							Log.d("yinan", "Entity!!!");/////////

					   BufferedReader br = new BufferedReader(new InputStreamReader(entity.getContent()));

							String str;

							Log.d("yinan", "OnClickListener");/////////

							while((str = br.readLine()) != null){

								Log.d("yinan", str);

							}

							

						} catch (ClientProtocolException e) {

							

							e.printStackTrace();

						} catch (IOException e) {

							

							e.printStackTrace();

						}

					}

					

				}.start();

				

			}

        	

        });

        

        

        

 

    }

}