android 向web服务器发送post请求并获取结果

android 向web服务器发送post请求并获取结果，因为 需要访问到网络必须要有权限，先在AndroidManifest.xml中加入如下配置：

 <uses-permission android:name="android.permission.INTERNET" /> 

 
发送post请求并获取结果的activity 代码如下：

package httppost.pack;  
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
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 org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class AndroidHttpPost extends Activity {
     /** Called when the activity is first created. */
     String action="http://www.beijibear.com/android_post.php";     
     HttpPost httpRequest=null;
     List <NameValuePair> params=null;
     HttpResponse httpResponse;
     TextView tv=null;
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         tv=(TextView)findViewById(R.id.textView1); 
        /*建立HttpPost连接*/
         httpRequest=new HttpPost(action); 
        /*Post运作传送变数必须用NameValuePair[]阵列储存*/  
         params=new ArrayList<NameValuePair>();
         params.add(new BasicNameValuePair("username","beijibear"));
         try {            
             //发出HTTP request 
             httpRequest.setEntity(new UrlEncodedFormEntity(params,HTTP.UTF_8));
             //取得HTTP response
             httpResponse=new DefaultHttpClient().execute(httpRequest);             
             //若状态码为200
             if(httpResponse.getStatusLine().getStatusCode()==200)       {                 
              //取出回应字串 
                    String strResult=EntityUtils.toString(httpResponse.getEntity());
                 tv.setText(strResult);
             }else{
                 tv.setText("Error Response"+httpResponse.getStatusLine().toString());
             }
         } catch (Exception e) {
             // TODO Auto-generated catch block 
            tv.setText(e.getMessage().toString());
         } 
    }
 }