java实现protocol传输的客户端和服务端的示例代码

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {

    private static final int PORT = 12345;

    public static void main(String[] args) {
        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
            System.out.println("Server is listening on port " + PORT);

            while (true) {
                Socket socket = serverSocket.accept();
                System.out.println("New client connected");

                new ClientHandler(socket).start();
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

class ClientHandler extends Thread {
    private Socket socket;

    public ClientHandler(Socket socket) {
        this.socket = socket;
    }

    public void run() {
        try (BufferedReader input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
             PrintWriter output = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()), true)) {

            String message;
            while ((message = input.readLine()) != null) {
                System.out.println("Received from client: " + message);
                output.println("Server: " + message);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;

public class Client {

    private static final String SERVER_ADDRESS = "localhost";
    private static final int SERVER_PORT = 12345;

    public static void main(String[] args) {
        try (Socket socket = new Socket(SERVER_ADDRESS, SERVER_PORT);
             BufferedReader input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
             PrintWriter output = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()), true);
             BufferedReader consoleInput = new BufferedReader(new InputStreamReader(System.in))) {

            String userInput;
            while ((userInput = consoleInput.readLine()) != null) {
                output.println(userInput);
                String response = input.readLine();
                System.out.println(response);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

javac Server.java
java Server

javac Client.java
java Client