2011-12-26 38 views
2

我開發了一個客戶端服務器java應用程序,並使用ObjectOutputStream和ObjectInputStream在客戶端和服務器進程之間發送和接收數據。我需要發送Array或對象或原始數據 ,但是當我使用ObjectOutputStream和ObjectInputStream發送和接收原始值(writeDouble(),readDouble(),writeUTF(),readUTF())時會出現問題。該計劃暫停並停止工作。爲什麼,這是什麼問題?在客戶端和服務器進程之間使用ObjectInputStream和ObjectOutputStream

這些都是我的節目的片段

// client program 

    ObjectOutputStream toServer; 
    ObjectInputStream fromServer; 

// Establish connection with the server 
      Socket socket = new Socket(host, 7000); 

      // Create an output stream to the server 
      toServer = new ObjectOutputStream(socket.getOutputStream()); 
      fromServer = new ObjectInputStream(socket.getInputStream()); 

double num1 = Double.parseDouble(jtf1.getText().trim()); 
        double num2 = Double.parseDouble(jtf2.getText().trim()); 
        try { 
         toServer.writeUTF("multiply"); 
         toServer.writeDouble(num1); 
         toServer.writeDouble(num2); 
         double result = fromServer.readDouble(); 
         res.setText(String.valueOf(result)); 
        } catch (IOException ex) { 
         System.err.println(ex); 
        } 

// server program 

private ObjectOutputStream outputToClient; 
    private ObjectInputStream inputFromClient; 

// Create a server socket 
      ServerSocket serverSocket = new ServerSocket(7000); 

while (true) { 
       // Listen for a new connection request 
       Socket socket = serverSocket.accept(); 
       System.out.println("connect "); 
       outputToClient = new ObjectOutputStream(socket.getOutputStream()); 
       // Create an input stream from the socket 
       inputFromClient = 
         new ObjectInputStream(socket.getInputStream()); 
       while(true) { 
       // Read from input 
       String command = inputFromClient.readUTF(); 
       System.out.println("receive command"); 
       checkRequest(command); 
       } 
       // Write to the file 
       //outputToFile.writeObject(object); 

      } 

public void checkRequest(String cmd){ 
     //Object o = null; 
     try{ 
     if(cmd.equals(MULTIBLY)){ 
      double x = inputFromClient.readDouble(); 
      double y = inputFromClient.readDouble(); 
      double result = x*y; 
      outputToClient.writeDouble(result); 
      System.out.println("send result"); 
     }else if (cmd.equals(DIVIDE)){ 
      int x = inputFromClient.readInt(); 
      int result = 1000/x; 
      outputToClient.writeDouble(result); 
     } 
     } catch(IOException io){ 

     } 
    } 

當我改變的ObjectOutputStream和ObjectInputStream的DataOutputStream類 和DataInputStream類的每一件事情去正確!

回答

10

您必須在客戶端的流上調用flush()以實際發送數據(如果套接字緩衝區未滿)。 你看到你的程序掛起,因爲客戶端不發送數據,服務器阻塞,等待永遠不會到來的數據。

+0

感謝它現在正常工作:) – sahar 2011-12-26 16:38:10

+0

在發送數據和接收數據之前使用flush()? – 2014-05-15 14:24:57

0

顯示的任何異常消息?程序暫停之前應該有一些消息。我知道這不是一個答案,但我沒有預防將其添加爲評論。

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