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带 GUI 的多线程客户端/服务器聊天室

[英]Multithreaded client/server Chat room with GUI

 原文  2020-11-23 01:16:37  6   1    java/ multithreading/ swing/ tcp/ chatroom

问题描述

我正在尝试使用 Java 制作一个带有 gui 的多线程客户端/服务器聊天室。 目前，我能够创建一个功能正常的注册页面和登录页面，这些页面使用我使用哈希映射实现的映射。 当我登录时，它没有像我预期的那样启动服务器或客户端，我也从服务器收到一条消息，说连接失败，但我无法确定为什么会这样。

客户

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import static java.rmi.server.LogStream.log;
import java.util.Scanner;


public class chatClient extends javax.swing.JFrame {

  
    Scanner scan ;
    Socket socket = null;
    DataInputStream input = null;
    DataOutputStream output = null;
    InetAddress ip;
    
    public chatClient() { //constructor
        try{                                             
            ip = InetAddress.getByName("localhost");
            socket = new Socket(ip, Constants.PORT);
            input = new DataInputStream(socket.getInputStream());
            output = new DataOutputStream(socket.getOutputStream());
            
            scan = new Scanner(System.in);
            
        }catch(UnknownHostException ex){
            log("Client : " + ex.getMessage());
        }catch(IOException ex){
            log("Client : " + ex.getMessage());
           
        }
            
            
        }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
    private void initComponents() {

        status = new javax.swing.JLabel();
        connectToServer = new javax.swing.JButton();
        privateConnection = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        messageArea = new javax.swing.JTextArea();
        inputMessage = new java.awt.TextField();
        sendMessage = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        status.setText("Logged in as:");

        connectToServer.setText("Connect to server");
        connectToServer.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                connectToServerActionPerformed(evt);
            }
        });

        privateConnection.setText("Private connection");

        messageArea.setColumns(20);
        messageArea.setRows(5);
        jScrollPane1.setViewportView(messageArea);

        inputMessage.setText("");

        sendMessage.setText("Send");
        sendMessage.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                sendMessageActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 382, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(inputMessage, javax.swing.GroupLayout.PREFERRED_SIZE, 246, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(sendMessage))
                    .addGroup(layout.createSequentialGroup()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(status, javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(connectToServer))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(privateConnection)))
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(status)
                .addGap(24, 24, 24)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(connectToServer)
                    .addComponent(privateConnection))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 310, Short.MAX_VALUE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(sendMessage, javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(inputMessage, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(14, 14, 14))
        );

        pack();
    }// </editor-fold>//GEN-END:initComponents

    private void connectToServerActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_connectToServerActionPerformed

    }//GEN-LAST:event_connectToServerActionPerformed

        private void sendMessage(){ 
        Thread sendMessage = new Thread(new Runnable() {
            
            @Override
            public void run() {
               while(true){
                  String message = scan.nextLine();
                  
                  try{
                      output.writeUTF(message);
                  }catch(IOException ex){
                      log("writeMessageThread : " + ex.getMessage());
                  }
               }
            }
        });
        sendMessage.start();
    }
    
    private void sendMessageActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_sendMessageActionPerformed
        sendMessage();
    }

        private void readMessage(){ //needs to implement the message area 
        Thread readMessage = new Thread(new Runnable() {
            
            @Override
            public void run() {
                while(true){
                    try{
                        String message = input.readUTF();
                        log(message);
                }catch(IOException ex){
                        log("readMessageThread : " + ex.getMessage());
                }
            }
            }
        });
        readMessage.start();
    }
    
    
    
    
    private void log(String message){
        System.out.println(message);

    }//GEN-LAST:event_sendMessageActionPerformed

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        chatClient client = new chatClient();
        client.readMessage();
        client.sendMessage();

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new chatClient().setVisible(true);
            }
        });

        
    }

    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton connectToServer;
    private java.awt.TextField inputMessage;
    private javax.swing.JScrollPane jScrollPane1;
    private static javax.swing.JTextArea messageArea;
    private javax.swing.JButton privateConnection;
    private javax.swing.JButton sendMessage;
    private javax.swing.JLabel status;
    // End of variables declaration//GEN-END:variables
}

服务器

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import static java.rmi.server.LogStream.log;
import java.util.ArrayList;
import java.util.List;


public class chatServer extends javax.swing.JFrame {

    /**
     * Creates new form chatServer
     */
    static List<ClientHandler> clients;
    ServerSocket serverSocket;
    static int usersOnline = 0;
    Socket socket;
    
    public chatServer() {
    clients = new ArrayList<>();
        try{
            serverSocket = new ServerSocket(Constants.PORT);
        }catch(IOException ex) {
            log("Server : " + ex.getMessage());
        }
    }   
    
    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
    private void initComponents() {

        jLabel1 = new javax.swing.JLabel();
        jButton1 = new javax.swing.JButton();
        jLabel2 = new javax.swing.JLabel();
        jScrollPane1 = new javax.swing.JScrollPane();
        messageArea = new javax.swing.JTextArea();
        jLabel3 = new javax.swing.JLabel();
        inputMessage = new java.awt.TextField();
        sendMessage = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jLabel1.setText("IP address:");

        jButton1.setText("Start Server");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jLabel2.setText("Users logged in:");

        messageArea.setColumns(20);
        messageArea.setRows(5);
        jScrollPane1.setViewportView(messageArea);

        jLabel3.setText("Server side");

        inputMessage.setText("textField1");
        inputMessage.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                inputMessageActionPerformed(evt);
            }
        });

        sendMessage.setText("Send");
        sendMessage.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                sendMessageActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                        .addComponent(sendMessage)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(jLabel2)
                        .addGap(45, 45, 45))
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(jScrollPane1, javax.swing.GroupLayout.Alignment.LEADING)
                            .addGroup(layout.createSequentialGroup()
                                .addComponent(jLabel3)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                    .addComponent(jButton1)
                                    .addComponent(jLabel1))))
                        .addGap(82, 82, 82))
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(inputMessage, javax.swing.GroupLayout.PREFERRED_SIZE, 251, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addContainerGap(323, Short.MAX_VALUE))))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel1)
                    .addComponent(jLabel3))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(jButton1)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 317, Short.MAX_VALUE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(inputMessage, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2)
                    .addComponent(sendMessage))
                .addContainerGap())
        );

        pack();
    }// </editor-fold>//GEN-END:initComponents

    
    private void inputMessageActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_inputMessageActionPerformed
        // TODO add your handling code here:
    }//GEN-LAST:event_inputMessageActionPerformed

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
        // TODO add your handling code here:
    }//GEN-LAST:event_jButton1ActionPerformed

    private void sendMessageActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_sendMessageActionPerformed

    }//GEN-LAST:event_sendMessageActionPerformed

    public static void main(String args[]) {
        chatServer server = new chatServer();
        server.waitingForConnection();
        java.awt.EventQueue.invokeLater(new Runnable() {        
        public void run() {
        new chatServer().setVisible(true);
            }
        });
    }
        /* Create and display the form */
    
    
     private void waitingForConnection(){
        log("Server running...");
        
        while(true) {
            try{
                socket = serverSocket.accept();
            }catch(IOException ex) {
            log("Waiting for connection : " + ex.getMessage()); 
            }
            
            log("Client accepted the connection : " + socket.getInetAddress());
            usersOnline++;
            
            ClientHandler handler = new ClientHandler(socket, "User" + usersOnline);
            
            Thread thread = new Thread(handler);
            addClient(handler);
            thread.start();
            
        }
    }
    
    


    public static List<ClientHandler> getClients(){
        return clients;
        
    }
    private void addClient(ClientHandler client){
        clients.add(client);
    }
    private void log(String message){
        System.out.println(message);
    }

       

    // Variables declaration - do not modify//GEN-BEGIN:variables
    private java.awt.TextField inputMessage;
    private javax.swing.JButton jButton1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JScrollPane jScrollPane1;
    private static javax.swing.JTextArea messageArea;
    private javax.swing.JButton sendMessage;
    // End of variables declaration//GEN-END:variables
}

登录

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package chatroomcwk;

import static com.sun.org.apache.xalan.internal.lib.ExsltDynamic.map;
import java.util.*; 
import java.lang.*; 
import java.awt.Component;
import java.awt.Frame;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
import javax.swing.JOptionPane;

public class login extends javax.swing.JFrame {

    /**
     * Creates new form login
     */
    public login() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
    private void initComponents() {

        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        passwordText = new javax.swing.JPasswordField();
        userText = new java.awt.TextField();
        jLabel3 = new javax.swing.JLabel();
        jButton2 = new javax.swing.JButton();
        jLabel4 = new javax.swing.JLabel();
        status = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jLabel1.setText("Username:");

        jLabel2.setText("Password:");

        passwordText.setText("");
        passwordText.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                passwordTextActionPerformed(evt);
            }
        });

        userText.setText("");
        userText.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                userTextActionPerformed(evt);
            }
        });

        jLabel3.setText("Login Page");

        jButton2.setText("Sign in");
        jButton2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton2ActionPerformed(evt);
            }
        });

        status.setText("Status");

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addGap(42, 42, 42)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                            .addGroup(layout.createSequentialGroup()
                                .addComponent(jLabel3)
                                .addGap(91, 91, 91))
                            .addGroup(layout.createSequentialGroup()
                                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                                    .addComponent(jLabel1)
                                    .addComponent(jLabel4)
                                    .addComponent(jLabel2))
                                .addGap(18, 18, 18)
                                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                                    .addComponent(userText, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                                    .addComponent(passwordText, javax.swing.GroupLayout.DEFAULT_SIZE, 176, Short.MAX_VALUE)))))
                    .addGroup(layout.createSequentialGroup()
                        .addContainerGap()
                        .addComponent(status)))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 130, Short.MAX_VALUE)
                .addComponent(jButton2)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(33, 33, 33)
                .addComponent(jLabel3)
                .addGap(45, 45, 45)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(userText, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel1))
                .addGap(10, 10, 10)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(passwordText, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel2))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 166, Short.MAX_VALUE)
                .addComponent(jLabel4)
                .addGap(9, 9, 9)
                .addComponent(jButton2)
                .addGap(21, 21, 21))
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(status)
                .addContainerGap())
        );

        pack();
    }// </editor-fold>//GEN-END:initComponents

    private void passwordTextActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_passwordTextActionPerformed
        // TODO add your handling code here:
    }//GEN-LAST:event_passwordTextActionPerformed
    
    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton2ActionPerformed

        String username = userText.getText();
        String password = passwordText.getText();
        Component frame = null;

      //Create a map for users where put username as key and password as value
      Map<String, String> usersMap = new HashMap<>();
      usersMap.put("user1", "password1");
      usersMap.put("user2", "password2");

      //Create a map for the admin where put username as key and password as value
      Map<String, String> adminMap = new HashMap<>();
      adminMap.put("Admin", "password");

      // Implement your authentication
      if(usersMap.get(username) != null){
           JOptionPane.showMessageDialog(frame, "You are successfully logged in!");
           setVisible(false); //you can't see me!
           dispose(); //Destroy the JFrame object
           chatClient second = new chatClient();
           second.setVisible(true); //displays the client page

      } else if (adminMap.get(username) != null){
            JOptionPane.showMessageDialog(frame, "You are successfully logged in!");
            setVisible(false); //you can't see me!
            dispose(); //Destroy the JFrame object
            chatServer third = new chatServer();
            third.setVisible(true); //displays the server page

      }else if (password.equals(map.usermap.get(username))){
            JOptionPane.showMessageDialog(frame, "You are successfully logged in!");
            setVisible(false); //you can't see me!
            dispose(); //Destroy the JFrame object
            chatServer third = new chatServer();
            third.setVisible(true); //displays the server page
      }    
      else {
            status.setText("Invalid username or password entered");
      }    
        
    
    }//GEN-LAST:event_jButton2ActionPerformed

    private void userTextActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_userTextActionPerformed
        // TODO add your handling code here:
    }//GEN-LAST:event_userTextActionPerformed

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        HashMap<String, String> users = new HashMap<String, String>();
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(login.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(login.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(login.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(login.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new login().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton jButton2;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private static javax.swing.JPasswordField passwordText;
    private javax.swing.JLabel status;
    private static java.awt.TextField userText;
    // End of variables declaration//GEN-END:variables
}

地图

import java.util.HashMap;
import java.util.Map;



public class map {
    
        public static HashMap<String, String> usermap = new HashMap<>();
        
        public HashMap<String, String> getUsers()
        {
            return usermap;
        }
     }

1 个解决方案

解决方案1
 2  2020-11-23 02:36:38

正如评论中提到的，您创建了太多对象。 例如，请看下面代码中标记的行：

public static void main(String args[]) {
    chatServer server = new chatServer();  // (A)
    server.waitingForConnection();
    java.awt.EventQueue.invokeLater(new Runnable() {        
        public void run() {
            new chatServer().setVisible(true); // (B)
        }
    });
}

在 (A) 线上，您创建了一个新的 chatServer 对象（为了符合 Java 命名约定，应该将其重命名为 ChatServer），然后您让这个对象等待 Swing 事件线程的连接，...很好.

但随后在 (B) 行中，您创建了一个全新的 chatServer 对象并将其显示为聊天服务器 GUI。 但是这个对象与在 (A) 行创建的对象完全不同，第一个对象发生的状态变化不会反映在第二个对象上，反之亦然，这意味着 GUI 将完全不知道任何聊天连接，而不是好的。

相反，您应该创建一个单独的 chatServer 对象，让它等待连接并显示它。 说做类似的事情：

public static void main(String args[]) {
    final chatServer server = new chatServer();  // (A)   ** make it a final local variable **
    server.waitingForConnection();
    java.awt.EventQueue.invokeLater(new Runnable() {        
        public void run() {
            // new chatServer().setVisible(true); // (B)  ** nope **
            server.setVisible(true);
        }
    });
}

聊天客户端的问题（和解决方案）非常相同。

请注意，如果这是我的程序，我会将类重命名为 ChatServer，并为连接等待创建一个特定的明确线程。 就像是：

public static void main(String args[]) {
    java.awt.EventQueue.invokeLater(new Runnable() {        
        public void run() {
            final ChatServer server = new ChatServer(); // ** rename the class 
            new Thread(() -> server.waitingForConnection()).start();
            server.setVisible(true);
        }
    });
}

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