java - 为什么我的两个客户都无法互相交流？ (Java服务器套接字)

我在连接两个客户端时遇到问题。我正在使用DataOutputStream和DataInputStream代替BufferedReader和PrintWritter吗？由于某些原因，即使我将服务器套接字和套接字通过本地主机和端口8000互连，它也不会相互连接。

我无法在这两个客户端之间发送消息。但是，是的，他们可以连接到服务器。但是，我希望我的客户彼此交流，以使其像在线聊天一样工作。

服务器端：

import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;

import javax.swing.*;

public class Server extends JFrame {
// Text area for displaying contents
private static JTextArea jta = new JTextArea();


public static void main(String[] args) {
    new Server();
}

public Server() {

    setLayout(new BorderLayout());
    add(new JScrollPane(jta), BorderLayout.CENTER);

    setTitle("Server");
    setSize(500, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true); // It is necessary to show the frame here!

    // Place text area on the frame
    try {
    // Create a server socket
    ServerSocket serverSocket = new ServerSocket(8000);
    jta.append("Server started at " + new Date() + '\n');
    try {
        while (true) {
            new Handler(serverSocket.accept()).start();
        }
    } finally {
        serverSocket.close();
    }

}
catch(IOException ex) {
    System.err.println(ex);
    }
}

public static class Handler extends Thread{

    Socket socket;
    DataInputStream inputFromClient;
    DataOutputStream outputToClient;

    public Handler(Socket socket){
        this.socket = socket;
    }

    public void run(){
        // Listen for a connection request
          //Socket socket = serverSocket.accept();
          try{
        // Create data input and output streams
           inputFromClient = new DataInputStream(socket.getInputStream());
           outputToClient = new DataOutputStream(socket.getOutputStream());

            while (true) {

            // Receive data from the client
            String message =inputFromClient.readUTF();

            System.out.println("Server: Receive input");

            jta.append("Word received from client: " + message + '\n');


            // DO converting process
            //String newMessage ="";
            //newMessage= message.toUpperCase();
            // Send data back to the client
            outputToClient.writeUTF(message);
            //jta.append("Word Converted: " + newMessage + '\n');

            }
          }catch(IOException ex) {
            System.err.println(ex);
            }
        }
    }
}

客户端

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Client extends JFrame {
// Text field for receiving data
private JTextField jtf = new JTextField();
// Text area to display contents
private JTextArea jta = new JTextArea();
// IO streams
private  DataOutputStream toServer;
private  DataInputStream fromServer;

public static void main(String[] args) {
    new Client();
}

public Client() {
// Panel p to hold the label and text field
    JPanel p = new JPanel();
    p.setLayout(new BorderLayout());
    p.add(new JLabel("Enter word: "), BorderLayout.WEST);
    p.add(jtf, BorderLayout.CENTER);
    jtf.setHorizontalAlignment(JTextField.RIGHT);

    setLayout(new BorderLayout());
    add(p, BorderLayout.NORTH);
    add(new JScrollPane(jta), BorderLayout.CENTER);

    jtf.addActionListener(new Listener()); // Register listener

    setTitle("Client");
    setSize(500, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true); // It is necessary to show the frame here!

    try {
    // Create a socket to connect to the server
     Socket socket = new Socket("localhost", 8000);
          // Socket socket = new Socket("130.254.204.36", 8000);
          // Socket socket = new Socket("drake.Armstrong.edu", 8000);

      // Create an input stream to receive data from the server
      fromServer = new DataInputStream(
        socket.getInputStream());

      // Create an output stream to send data to the server
      toServer =
        new DataOutputStream(socket.getOutputStream());


    }
    catch (IOException ex) {
    jta.append(ex.toString() + '\n');
    }
}

private class Listener implements ActionListener {
    @Override
    public void actionPerformed(ActionEvent e) {
        try {
        // Get the data from the text field
        String message = (jtf.getText().trim());

        // Send the data to the server
         toServer.writeUTF(message);

        // Get data from the server
         String serverMessage = fromServer.readUTF();
         System.out.println("from server");

        // Display to the text area

        jta.append("Word is " + message + "\n");
        jta.append("Word received from the server is "
          + serverMessage + '\n');
        toServer.flush();

        }
        catch (IOException ex) {
        System.err.println(ex);
        }
    }
}
}

最佳答案

您的软件并非旨在处理客户端与客户端之间的通信。

为此，您必须：


将客户端处理程序存储在服务器上（不将其丢弃；使用诸如LinkedList之类的动态内容）
向处理程序添加一个方法，该方法允许向该处理程序表示的客户端发送任意消息
在处理程序中接收客户端消息

将它们传递给服务器
使用发送方法将消息发送到列表中的客户端





我有点像1999年“我只能给你看门。你是必须走过的门。”但是SO似乎今天看到了不同。所以我们开始。

服务器：

import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;

import javax.swing.*;

public class Server extends JFrame {
// Text area for displaying contents
private static JTextArea jta = new JTextArea();
LinkedList<Handler> handlers = new LinkedList<Handler>();

public static void main(String[] args) {
    new Server();
}

public void sendmessagetoall(String message)
{
    for(Handler current : handlers)
    {
        try
        {
            current.writeMessage(message);
        }
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

public Server() {

    setLayout(new BorderLayout());
    add(new JScrollPane(jta), BorderLayout.CENTER);

    setTitle("Server");
    setSize(500, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true); // It is necessary to show the frame here!

    // Place text area on the frame
    try {
    // Create a server socket
    ServerSocket serverSocket = new ServerSocket(8000);
    jta.append("Server started at " + new Date() + '\n');
    try {
        while (true) {
            Handler noob =  new Handler(serverSocket.accept(),this);
            handlers.add(noob);
            noob.start();
        }
    } finally {
        serverSocket.close();
    }

}
catch(IOException ex) {
    System.err.println(ex);
    }
}

public static class Handler extends Thread{

    Socket socket;
    Server parent;
    DataInputStream inputFromClient;
    DataOutputStream outputToClient;

    public Handler(Socket socket, Server parent){
        this.socket = socket;
        this.parent = parent;
    }

    public void writeMessage(String message) throws IOException
    {
        outputToClient.writeUTF(message);
    }

    public void run(){
        // Listen for a connection request
          //Socket socket = serverSocket.accept();
          try{
        // Create data input and output streams
           inputFromClient = new DataInputStream(socket.getInputStream());
           outputToClient = new DataOutputStream(socket.getOutputStream());

            while (true) {

            // Receive data from the client
            String message =inputFromClient.readUTF();

            System.out.println("Server: Receive input");

            jta.append("Word received from client: " + message + '\n');


            // DO converting process
            //String newMessage ="";
            //newMessage= message.toUpperCase();
            // Send data back to the client
            //writeMessage(message);
            parent.sendmessagetoall(message);
            //jta.append("Word Converted: " + newMessage + '\n');

            }
          }catch(IOException ex) {
            System.err.println(ex);
            }
        }
    }
}

客户：

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class Client extends JFrame {
// Text field for receiving data
private JTextField jtf = new JTextField();
// Text area to display contents
private JTextArea jta = new JTextArea();
// IO streams
private  DataOutputStream toServer;
private  DataInputStream fromServer;

public static void main(String[] args) {
    new Client();
}

public Client() {
// Panel p to hold the label and text field
    JPanel p = new JPanel();
    p.setLayout(new BorderLayout());
    p.add(new JLabel("Enter word: "), BorderLayout.WEST);
    p.add(jtf, BorderLayout.CENTER);
    jtf.setHorizontalAlignment(JTextField.RIGHT);

    setLayout(new BorderLayout());
    add(p, BorderLayout.NORTH);
    add(new JScrollPane(jta), BorderLayout.CENTER);

    jtf.addActionListener(new Listener()); // Register listener

    setTitle("Client");
    setSize(500, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true); // It is necessary to show the frame here!

    try {
    // Create a socket to connect to the server
     Socket socket = new Socket("localhost", 8000);
          // Socket socket = new Socket("130.254.204.36", 8000);
          // Socket socket = new Socket("drake.Armstrong.edu", 8000);

      // Create an input stream to receive data from the server
      fromServer = new DataInputStream(
        socket.getInputStream());

      // Create an output stream to send data to the server
      toServer =
        new DataOutputStream(socket.getOutputStream());

      new Thread(new Runnable(){

        @Override
        public void run()
        {
            while(true)
            {
                String serverMessage = "";
                try
                {
                    serverMessage = fromServer.readUTF();
                }
                catch (IOException e)
                {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                jta.append("Word received from the server is "
                          + serverMessage + '\n');
            }

        }})
        .start();


    }
    catch (IOException ex) {
    jta.append(ex.toString() + '\n');
    }
}

private class Listener implements ActionListener {
    @Override
    public void actionPerformed(ActionEvent e) {
        try {
        // Get the data from the text field
        String message = (jtf.getText().trim());

        // Send the data to the server
         toServer.writeUTF(message);

        // Get data from the server

         System.out.println("from server");

        // Display to the text area

        jta.append("Word is " + message + "\n");

        toServer.flush();

        }
        catch (IOException ex) {
        System.err.println(ex);
        }
    }
}
}

快速而肮脏地编辑您的代码。
这不能处理断开连接并向所有客户端分发消息的客户端，但是您应该有一个起点。