请写一个简单的代理程序的Java代码

好的，以下是一个简单的Java代理程序的代码示例：

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

public class ProxyServer {
    public static void main(String[] args) {
        try {
            ServerSocket serverSocket = new ServerSocket(8080);
            while (true) {
                Socket clientSocket = serverSocket.accept();

                BufferedReader reader = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
                BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));

                String request = reader.readLine();

                String[] tokens = request.split(" ");
                String method = tokens[0];
                String url = tokens[1];
                String version = tokens[2];

                URL serverUrl = new URL(url);
                HttpURLConnection serverConnection = (HttpURLConnection) serverUrl.openConnection();

                serverConnection.setRequestMethod(method);

                BufferedReader serverReader = new BufferedReader(new InputStreamReader(serverConnection.getInputStream()));

                String responseStatusLine = serverConnection.getHeaderField(0);
                writer.write(responseStatusLine + "\r\n");

                String line;
                while ((line = serverReader.readLine()) != null) {
                    writer.write(line + "\r\n");
                }

                serverReader.close();
                writer.flush();
                writer.close();
                reader.close();
                clientSocket.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

这个程序是一个简单的代理服务器，它监听8080端口，并在收到客户端的连接请求时，将客户端请求转发到指定的URL，并将响应返回给客户端。这个程序使用Java的Socket和URL类来实现代理服务器的功能。