如何实现JAVA底层网络通信协议

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

public class Server {
    public static void main(String[] args) {
        try {
            // 创建ServerSocket，并指定端口号
            ServerSocket serverSocket = new ServerSocket(8888);
            
            // 监听客户端的连接请求
            Socket socket = serverSocket.accept();
            
            // 获取输入流，用于接收客户端发送的数据
            InputStream inputStream = socket.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
            
            // 获取输出流，用于向客户端发送数据
            OutputStream outputStream = socket.getOutputStream();
            PrintWriter printWriter = new PrintWriter(outputStream);
            
            // 读取客户端发送的数据
            String message = bufferedReader.readLine();
            System.out.println("收到客户端的消息：" + message);
            
            // 向客户端发送数据
            printWriter.println("Hello, client!");
            printWriter.flush();
            
            // 关闭连接
            socket.close();
            serverSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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

public class Client {
    public static void main(String[] args) {
        try {
            // 创建Socket，并指定服务器的IP地址和端口号
            Socket socket = new Socket("localhost", 8888);
            
            // 获取输出流，用于向服务器发送数据
            OutputStream outputStream = socket.getOutputStream();
            PrintWriter printWriter = new PrintWriter(outputStream);
            
            // 获取输入流，用于接收服务器发送的数据
            InputStream inputStream = socket.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
            
            // 向服务器发送数据
            printWriter.println("Hello, server!");
            printWriter.flush();
            
            // 读取服务器的响应
            String message = bufferedReader.readLine();
            System.out.println("收到服务器的消息：" + message);
            
            // 关闭连接
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}