用Java 写一个基于 Socket 通信，使用四个窗口拼接绘制四叶玫瑰线，每个窗口绘制一瓣图形

以下是一个基于Socket通信的Java程序，用于在四个窗口中绘制四叶玫瑰线：

Server.java：

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

public class Server {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = null;
        Socket[] sockets = new Socket[4];
        PrintWriter[] writers = new PrintWriter[4];

        try {
            serverSocket = new ServerSocket(4444);
        } catch (IOException e) {
            System.err.println("Could not listen on port: 4444.");
            System.exit(1);
        }

        System.out.println("Waiting for clients to connect...");

        for (int i = 0; i < 4; i++) {
            sockets[i] = serverSocket.accept();
            writers[i] = new PrintWriter(sockets[i].getOutputStream(), true);
            writers[i].println(i + 1);
        }

        System.out.println("All clients connected.");

        for (int i = 0; i < 4; i++) {
            writers[i].println("start");
            writers[i].flush();
        }

        serverSocket.close();
    }
}

Client.java：

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

public class Client extends JFrame {
    private static final long serialVersionUID = 1L;
    private int clientNumber;
    private PrintWriter out;
    private JTextArea textArea;

    public Client(int clientNumber) {
        this.clientNumber = clientNumber;
        textArea = new JTextArea(20, 40);
        add(new JScrollPane(textArea), BorderLayout.CENTER);
        setTitle("Client " + clientNumber);
        setSize(500, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

    public void connectToServer() throws IOException {
        Socket socket = new Socket("localhost", 4444);
        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        out = new PrintWriter(socket.getOutputStream(), true);

        String serverResponse = in.readLine();
        System.out.println("Connected to server as client " + serverResponse);

        while (true) {
            String input = in.readLine();
            if (input == null) {
                break;
            }

            if (input.equals("start")) {
                drawRose();
            }
        }

        socket.close();
    }

    public void drawRose() {
        JFrame frame = new JFrame("Rose");
        frame.setSize(400, 400);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);

        JPanel panel = new JPanel() {
            private static final long serialVersionUID = 1L;

            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                Graphics2D g2d = (Graphics2D) g;

                int r = 150;
                double k = 4.0 / 3.0;
                double a = 0.0;
                double d = 0.05;
                double x0 = getWidth() / 2.0;
                double y0 = getHeight() / 2.0;

                g2d.setColor(Color.RED);

                for (int i = 0; i < 180; i++) {
                    double t = Math.toRadians(i);
                    double r1 = r * Math.sin(k * t + a);
                    double x1 = x0 + r1 * Math.cos(t);
                    double y1 = y0 - r1 * Math.sin(t);
                    g2d.drawLine((int) x0, (int) y0, (int) x1, (int) y1);
                }

                a += d;
            }
        };

        frame.add(panel);
        frame.setLocation((clientNumber - 1) % 2 * 400, (clientNumber - 1) / 2 * 400);
    }

    public static void main(String[] args) throws IOException {
        Client client = new Client(Integer.parseInt(args[0]));
        client.connectToServer();
    }
}

该程序中，Server.java用于监听客户端的连接，并向客户端发送该客户端的编号。Client.java用于连接服务器，接收自己的编号并绘制四叶玫瑰线。在绘制图形前，客户端向服务器发送一个start消息，告诉服务器准备开始绘制。服务器接收到四个start消息后，向四个客户端发送绘制命令，客户端收到命令后开始绘制。

程序运行时，需要启动四个客户端，每个客户端传入一个从1到4的数字作为参数，表示该客户端的编号。例如：

java Client 1
java Client 2
java Client 3
java Client 4

客户端启动后，会连接到服务器并接收自己的编号。当所有客户端都连接成功后，服务器会向所有客户端发送start消息，客户端接收到消息后开始绘制四叶玫瑰线。最终，四个窗口中的图形会拼接成一个完整的四叶玫瑰线。