响应没有进入（android套接字编程/ tcp/ip套接字编程）

Question

我正在开发一个Android应用程序，我必须在服务器上发送位置数据并获取作业数据作为响应，这样所有通信都会生成但当我试图从服务器读取没有任何输出的响应，并且没有任何响应来临时，我困扰于一件事情，所以请帮助我摆脱困境。以下是我的代码。提前致谢。

public static class MyClientTask extends AsyncTask<Void, Void, Void> { 
     String dstAddress; 
     int dstPort; 
     String response = ""; 
     String s; 
     String red; 
     String loc; 
     String msg; 
     Socket socket = null; 
     DataOutputStream dataOutputStream = null; 
     DataInputStream dataInputStream = null; 
     InputStream is=null; 
     BufferedReader br=null; 
     public MyClientTask(String addr, int port,String msg){ 
     dstAddress = addr; 
     dstPort = port; 
     loc=msg; 
     } 
     @Override 
     protected Void doInBackground(Void... arg0) { 

      try { 
        socket = new Socket(dstAddress, dstPort); 
        socket.setKeepAlive(true); 
        dataOutputStream = new DataOutputStream(socket.getOutputStream()); 
        is=socket.getInputStream(); 
       socket.setSoTimeout(60*1000); 
        dataInputStream = new DataInputStream(is); 

        Log.i("socket connect","socket OK"); 
        dataOutputStream.writeUTF(loc); 
        while (dataInputStream == null) 
        { 
         ////this part is not working 
         Log.i("DEV", "sleep "+is.available()); 
         android.os.SystemClock.sleep(100); 
        } 
        br=new BufferedReader(new InputStreamReader(dataInputStream)); 
        String st = null; 
        while(socket.isConnected()){ 
         st = br.readLine(); 
         } 
        Log.w("server response", "says Server = " + st); 

        Dbase db2=new Dbase(mcontext); 
        db2.addresponse(new info(st)); 
        Log.w("second time server response", "says 2ndTime Server = " + st); 
       } catch (UnknownHostException e) { 
        Log.e("at exception", "at thread unknownHost " + e.getMessage()); 
        e.printStackTrace(); 
       } catch (IOException e) { 
        Log.e("io exception", "at thread IO " + e.getMessage()); 
        e.printStackTrace(); 
       } 

       finally{ 
        Log.i("on finally block", "finally"); 
        if (dataOutputStream != null){ 
         try { 
          dataOutputStream.close(); 
         } catch (IOException e) { 
          Log.e("io eception", "at thread dataoutput IO " + e.getMessage()); 
          e.printStackTrace(); 
         } 
        } 

        if (dataInputStream != null){ 
         try { 
          dataInputStream.close(); 
         } catch (IOException e) { 
          Log.e("data input exception", "at thread datainput IO " + e.getMessage()); 
          e.printStackTrace(); 
         } 
        } 
        if (socket != null){ 
         try { 
          Log.i("socket", "socket closed"); 
          socket.close(); 
         } catch (IOException e) { 
          Log.e("socket exception", "at thread finally IO " + e.getMessage()); 
          e.printStackTrace(); 
         } 
        } 
       } 
       return null; 
      } 

      @Override 
      protected void onPreExecute() { 
       super.onPreExecute(); 
       //displayProgressBar("Downloading..."); 
      } 


      @Override 
      protected void onPostExecute(Void result) { 
       super.onPostExecute(result); 
      } 
     } 

Answer 1

使用不当InputStream.available方法。此方法不会尝试检索数据。实际上，此方法的大多数实现始终返回0.请参阅Inputstream available reference。 我建议您只删除可用的检查，并根据需要让readLine块。 BufferedReader.ready也是如此 - 通常这并不表示在尝试阅读时您将获得任何数据，因此此调用也无用。