问Android rest rest服务问题

EN

package com.rest;
import java.io.IOException;  

import android.app.Activity;  
import android.os.Bundle;  
import android.util.Log;  
import android.view.View;  
import android.widget.Button;  
import android.widget.EditText;  
import android.widget.Toast;

import org.apache.http.client.ClientProtocolException;  
import org.apache.http.client.HttpClient;  
import org.apache.http.client.ResponseHandler;  
import org.apache.http.impl.client.BasicResponseHandler;  
import org.apache.http.client.methods.HttpGet;  
import org.apache.http.impl.client.DefaultHttpClient;  
import android.app.Activity;
import android.os.Bundle;

public class rest extends Activity {
    /** Called when the activity is first created. */

    String URL = "http://sc2.mystreamserver.com:8050/admin.cgi?mode=viewxml";  
       String result = "";  
        String deviceId = "xxxxx" ;  
       final String tag = "Your Logcat tag: ";  
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);




          /** Called when the activity is first created. */  

        callWebService();  

                final EditText txtSearch = (EditText)findViewById(R.id.txtSearch);  
             txtSearch.setOnClickListener(new EditText.OnClickListener(){  
                public void onClick(View v){txtSearch.setText("");}  
             });  

               final Button btnSearch = (Button)findViewById(R.id.btnSearch);  
                btnSearch.setOnClickListener(new Button.OnClickListener(){  
                    public void onClick(View v) {  
                        String query = txtSearch.getText().toString();  


                   }  
               });  

          } // end onCreate()  

           public void callWebService(){  
              HttpClient httpclient = new DefaultHttpClient();  
               HttpGet request = new HttpGet(URL);  
               request.addHeader("username","    "); 
               request.addHeader("pass","   ");  
               ResponseHandler<String> handler = new BasicResponseHandler();  
               try {  
                  result = httpclient.execute(request, handler);  
                } catch (ClientProtocolException e) {  
                    result=e.toString(); 
                } catch (IOException e) {  
                    result=e.toString();  
                }  
                httpclient.getConnectionManager().shutdown();  
               Log.i(tag, result);  
               Toast.makeText(rest.this, result, Toast.LENGTH_SHORT).show();
            } // end callWebService()  

 }