服務器端工作正常客戶端在Android中給出0

Question

在下面的代碼中System.out.println（groupdetails）;給出0，但parms得到了正確的值。

從服務器端它工作正常，但從客戶端給0。我在哪裏犯了一個錯誤？

的java

protected void onCreate(Bundle savedInstanceState) 
    {  
     super.onCreate(savedInstanceState); 
      if (android.os.Build.VERSION.SDK_INT > 9) { 
       StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder() 
       .permitAll().build(); 
       StrictMode.setThreadPolicy(policy); 
      } 
     setContentView(R.layout.list_screen); 

     friendAdapter = new FriendListAdapter(this); 
     try { 
      imService=Login.imService; 
      String groupdetails = imService.DispalyGroupDetails(imService.getUsername()); 
      System.out.println(groupdetails); 
     } catch (UnsupportedEncodingException e) { 

      e.printStackTrace(); 
     }  

    } 

imService.DispalyGroupDetails

public String DispalyGroupDetails(String username) throws UnsupportedEncodingException { 


      String params = 
         "username="+ URLEncoder.encode(this.username,"UTF-8") + 
         "&password="+ URLEncoder.encode(this.password,"UTF-8") + 
         "&action=" + URLEncoder.encode("DispalyGroupFDetails","UTF-8")+ 
         "&"; 

      Log.i("PARAMS", params); 
      return socketOperator.sendHttpRequest(params);  


    } 

socketOperator.sendHttpRequest

public SocketOperator(IAppManager appManager) { 
    } 


    public String sendHttpRequest(String params) 
    {  
     URL url; 
     String result = new String(); 



     try 
     { 
      url = new URL(AUTHENTICATION_SERVER_ADDRESS); 
      HttpURLConnection connection; 
      connection = (HttpURLConnection) url.openConnection(); 
      connection.setDoOutput(true); 

      PrintWriter out = new PrintWriter(connection.getOutputStream()); 

      out.println(params); 
      out.close(); 

      BufferedReader in = new BufferedReader(
        new InputStreamReader(
          connection.getInputStream())); 
      String inputLine; 

      while ((inputLine = in.readLine()) != null) { 
       result = result.concat(inputLine);    
      } 
      in.close();   
     } 
     catch (MalformedURLException e) { 
      e.printStackTrace(); 
     } 
     catch (IOException e) { 
      e.printStackTrace(); 
     }   

     if (result.length() == 0) { 
      result = HTTP_REQUEST_FAILED; 
     } 

     return result; 


    } 

Answer 1

很可能imService是null，因爲您正在開始綁定服務作爲正常服務，因此imService未初始化。啓動綁定的服務使用bindService代替startService：

Intent intent=new Intent(Login.this, IMService.class); 
this.bindService(intent,mConnection,Context.BIND_AUTO_CREATE);