2011-12-26 73 views
2

我开发了一个客户端服务器java应用程序,并使用ObjectOutputStream和ObjectInputStream在客户端和服务器进程之间发送和接收数据。我需要发送Array或对象或原始数据 ,但是当我使用ObjectOutputStream和ObjectInputStream发送和接收原始值(writeDouble(),readDouble(),writeUTF(),readUTF())时会出现问题。该计划暂停并停止工作。为什么,这是什么问题?在客户端和服务器进程之间使用ObjectInputStream和ObjectOutputStream

这些都是我的节目的片段

// 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){ 

     } 
    } 

当我改变的ObjectOutputStream和ObjectInputStream的DataOutputStream类 和DataInputStream类的每一件事情去正确!

回答

10

您必须在客户端的流上调用flush()以实际发送数据(如果套接字缓冲区未满)。 你看到你的程序挂起,因为客户端不发送数据,服务器阻塞,等待永远不会到来的数据。

+0

感谢它现在正常工作:) – sahar 2011-12-26 16:38:10

+0

在发送数据和接收数据之前使用flush()? – 2014-05-15 14:24:57

0

显示的任何异常消息?程序暂停之前应该有一些消息。我知道这不是一个答案,但我没有预防将其添加为评论。

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