Question

因此，我刚刚学习了如何用Java制作//global directive Vue.directive('flab',{ inserted:function(el){ el.setAttribute('fab'); el.setAttribute('flat') } }) //while using v-btn anywhere (as you have global directive now) <v-btn v-flab> //using directive flab with v- prefix {{btnName}} </v-btn>和所有这些好东西，所以我的第一次尝试是从客户端收到一条消息，然后客户端崩溃了。应该发生的是从客户端收到一条消息，如果该消息与此相等，则将数据发送回去。但是，即使消息是正确的，也无法触发socket函数来确定消息是否正确。

即使我删除了if函数以检查字符串是否正确，该程序仍然冻结。顺便说一句，我的服务器是一个控制台应用程序，而我的客户端是一个SWT应用程序。

以下是带有删除的if函数的服务器代码：

if

和客户端（按下按钮时将触发）：

try {
    System.out.println("Waiting for a connection...");
    // Start a server
    ServerSocket server = new ServerSocket(3211);
    // Listen for anyone at that port
    Socket socket = server.accept();
    System.out.println("The client has connected!");
    // Get the data being sent in
    DataInputStream inputStream = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
    DataOutputStream ouputStream = new DataOutputStream(socket.getOutputStream());
    // Turn that into UTF-8
    String data = inputStream.readUTF();
    System.out.println("Received " + data);
    ouputStream.writeUTF("Great!");
    System.out.println("Awesome!");
    socket.close();
    inputStream.close();
    ouputStream.close;
    server.close();
    System.out.println("Socket closed\n-----------------------------");
}
catch(IOException e) {
    System.out.println(e);
}

当我按下按钮尝试并开始连接（服务器已在运行）时，客户端立即冻结。它甚至不发送任何“连接服务器”之类的东西。

任何想法都出了什么问题，以及如何解决此问题？

Answer 1

您的套接字无法发送数据，因为您没有在.flush()引用中调用outputstream方法。使用此方法，您不必在流上显式编写flush()和close()方法

服务器代码

System.out.println("Waiting for a connection...");
// Start a server
try (ServerSocket server = new ServerSocket(3211)) {
    // Listen for anyone at that port
    try (Socket socket = server.accept()) {
        System.out.println("The client has connected!");
        // Get the data being sent in
        try (DataInputStream inputStream = new DataInputStream(new BufferedInputStream(socket.getInputStream()))) {
            try (DataOutputStream ouputStream = new DataOutputStream(socket.getOutputStream())) {
                // Turn that into UTF-8
                String data = inputStream.readUTF();
                System.out.println("Received " + data);
                ouputStream.writeUTF("Great!");
                System.out.println("Awesome!");
           }
        }
    }
    System.out.println("Socket closed\n-----------------------------");
} catch (IOException e) {
    System.out.println(e);
}

客户代码

try {
    allMessagesTextBox.setText(allMessagesTextBox.getText() + "\nConnecting to  the server...");
    try (Socket socket = new Socket("127.0.0.1", 3211)) {
        allMessagesTextBox.setText(allMessagesTextBox.getText() + "\nConnected to the server!");
        try (DataInputStream input = new DataInputStream(socket.getInputStream())) {
            try (DataOutputStream output = new DataOutputStream(socket.getOutputStream())) {
                output.writeUTF("sweet");
            }
            String data = input.readUTF();
            System.out.println(String.format("data received from server '%s':\n", data));
            allMessagesTextBox.setText(allMessagesTextBox.getText() + "\nSERVER: " +  data);
        }
    }
} catch (IOException er) {
    allMessagesTextBox.setText(allMessagesTextBox.getText() + "\n" + er);
}

服务器上的输出

Waiting for a connection...
The client has connected!
Received sweet
Awesome!
Socket closed
-----------------------------

客户端上的输出

data received from server 'Great!':

现在要解决代码中的问题。

查看您编写的DataInputStream input = new DataInputStream(System.in);而不是DataInputStream input = new DataInputStream(socket.getInputStream())的客户端代码

这导致无法从服务器接收消息

Answer 2

您的客户正在读取System.in。它应该从套接字输入流中读取。

NB您只需要关闭套接字的另一个输出流即可。如有必要，将刷新它并关闭输入流和套接字。目前，您不仅完成了超过必要的交易，而且顺序错误，

服务器套接字未使用Java发送回数据

2 个答案: