java - 客户端 - 服务器 ObjectInputStream 错误

Question

我的代码是这样的

try
    {
        //Connect to the login server
        socket = new Socket(hostName , 15000);
        out = new ObjectOutputStream(socket.getOutputStream());
        input = new ObjectInputStream(socket.getInputStream());

                    .. //perform the login , if the login succeed make answ=1;
    }
    catch (UnknownHostException e) {
        System.err.println("Unknown host: " + hostName);
        StatusLabel.setText("Unknown host");
    }
    catch (ConnectException e) {
        System.err.println("Connection refused by host: " + hostName);
        StatusLabel.setText("Connection refused by host, server is down.");
    }
    catch (IOException e) {
        e.printStackTrace();
    }
    finally {
        try 
        {
            //Finaly closing the connection
            socket.close();
            System.out.flush();
            System.out.println("Socket Closed");
                            //closing the output and input stream
            out.close();
            input.close();
            setVisible(false); //closing the window
        }
        catch (IOException e ) {
            System.out.println("Couldn't close socket");
        }
    }
    if(answ==1) //if the login suceed start the class for the game
    {
        Gumoku_Graphics g = new Gumoku_Graphics();
        g.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        g.Play();
    }

在Gumoku_Graphics()内部我调用这个类来执行与游戏服务器的连接

Game n = new Game();
status=n.Connection();

这是

 public int Connection()  
{
    try {
        socket = new Socket(hostName, 15432);
        System.out.println("socket ok\n");

        out = new ObjectOutputStream(socket.getOutputStream());
        System.out.println("out ok\n");


        input = new ObjectInputStream(socket.getInputStream());
        System.out.println("socket,out,input ok\n");
        return 1;
    }

    catch (UnknownHostException e) {
        System.err.println("Unknown host: " + hostName);
        return 0;
    }
    catch (ConnectException e) {
        System.err.println("Connection refused by host: " + hostName);
        return 0;
    }
    catch (IOException e) {
        e.printStackTrace();
        return 0;
    }
}

并且每次它停止在“input = new ObjectInputStream(socket.getInputStream());”它无法做到这一点并且卡在那里。它打印“socket ok”、“out ok”并且卡在那里。有什么问题？我做错了什么？

Answer 1

来自ObjectInputStream documentation :

Creates an ObjectInputStream that reads from the specified InputStream. A serialization stream header is read from the stream and verified. This constructor will block until the corresponding ObjectOutputStream has written and flushed the header.

正如引用的那样，调用将阻塞，直到可以读取 header 。在继续此调用之前，您需要从套接字接收一些数据。