Java实现多线程聊天室

实现多线程聊天室，在Java中可以通过使用Socket和Thread来实现。

具体步骤如下：

1.创建服务器端
- 创建ServerSocket对象，并设置端口号
- 创建Socket对象，以接受客户端请求
- 使用Thread创建一个线程，以接受客户端发来的消息，并将消息广播给其他客户端
- 使用ArrayList存储客户端（每个客户端都对应一个Socket对象）
- 使用while循环，以接受客户端请求并处理

示例1：

下面是创建线程的示例代码。

public class ChatServer {

    private ArrayList clientList = new ArrayList();
    private ServerSocket serverSocket;

    public void start() {
        try {
            serverSocket = new ServerSocket(1024);
            System.out.println("server start...");
            while (true) {
                Socket socket = serverSocket.accept();
                System.out.println("accept client:" + socket.getInetAddress());
                ChatHandler handler = new ChatHandler(socket, clientList);
                new Thread(handler).start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

class ChatHandler implements Runnable {

    private Socket socket;

    private BufferedReader reader;
    private PrintWriter writer;
    private ArrayList clientList;

    public ChatHandler(Socket socket, ArrayList clientList) {
        this.socket = socket;
        this.clientList = clientList;
        try {
            reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            writer = new PrintWriter(socket.getOutputStream(), true);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        try {
            String line;
            while ((line = reader.readLine()) != null) {
                broadcast(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void broadcast(String msg) {
        for (int i = 0; i < clientList.size(); i++) {
            Socket s = (Socket) clientList.get(i);
            if (s != this.socket) {
                try {
                    PrintWriter pw = new PrintWriter(s.getOutputStream(), true);
                    pw.println(msg);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

示例2：

下面是客户端实现的示例代码。

public class ChatClient extends JFrame {

    private JTextArea msgarea = new JTextArea();
    private JTextField msginput = new JTextField();
    private JButton btn = new JButton("发送");

    private PrintWriter pw;

    public ChatClient() {
        init();
        connect();
    }

    private void init() {
        this.setSize(400, 400);
        this.setLayout(new BorderLayout());
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);

        JScrollPane sp = new JScrollPane(msgarea);
        msgarea.setEditable(false);
        this.add(sp, BorderLayout.CENTER);

        JPanel bottomPanel = new JPanel();
        bottomPanel.setLayout(new BorderLayout());
        bottomPanel.add(msginput, BorderLayout.CENTER);
        bottomPanel.add(btn, BorderLayout.EAST);
        this.add(bottomPanel, BorderLayout.SOUTH);
        btn.addActionListener(e -> {
            String msg = msginput.getText();
            pw.println(msg);
            msginput.setText("");
        });
    }

    private void connect() {
        try {
            Socket socket = new Socket("localhost", 1024);
            pw = new PrintWriter(socket.getOutputStream(), true);
            BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            new Thread(() -> {
                String line;
                try {
                    while ((line = br.readLine()) != null) {
                        msgarea.append(line + "\n");
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }).start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        new ChatClient().setVisible(true);
    }
}

至此，Java实现多线程聊天室的完整攻略就讲解完了。如果你想了解更多关于Java多线程编程，可以参考Java的官方文档或者相关教程。