写一个java gateway的一个网关

以下是一个简单的Java网关示例：

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class Gateway {
    public static void main(String[] args) {
        int port = 8080; // 网关监听的端口号
        try {
            ServerSocket serverSocket = new ServerSocket(port);
            System.out.println("Gateway listening on port " + port);
            while (true) {
                Socket clientSocket = serverSocket.accept();
                System.out.println("New client connected: " + clientSocket.getInetAddress().getHostAddress());
                GatewayThread gatewayThread = new GatewayThread(clientSocket);
                gatewayThread.start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static class GatewayThread extends Thread {
        private Socket clientSocket;

        public GatewayThread(Socket clientSocket) {
            this.clientSocket = clientSocket;
        }

        public void run() {
            try {
                InputStream clientInputStream = clientSocket.getInputStream();
                OutputStream clientOutputStream = clientSocket.getOutputStream();

                // 从客户端读取数据
                byte[] buffer = new byte[1024];
                int bytesRead = clientInputStream.read(buffer);
                String request = new String(buffer, 0, bytesRead);
                System.out.println("Request received from client: " + request);

                // 将数据发送到后端服务器
                Socket serverSocket = new Socket("backend-server-ip", 8080);
                OutputStream serverOutputStream = serverSocket.getOutputStream();
                serverOutputStream.write(request.getBytes());

                // 从后端服务器读取响应并将其发送回客户端
                InputStream serverInputStream = serverSocket.getInputStream();
                bytesRead = serverInputStream.read(buffer);
                String response = new String(buffer, 0, bytesRead);
                System.out.println("Response received from server: " + response);
                clientOutputStream.write(response.getBytes());

                // 关闭套接字和流
                clientSocket.close();
                serverSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

该网关监听指定端口上的传入连接，并将接收到的HTTP请求转发到后端服务器。它还将从后端服务器接收响应并将其发送回客户端。您需要将`backend-server-ip`替换为您的后端服务器的IP地址。此示例仅用于参考，您可能需要根据实际需求进行修改。