()编写java基于 TCP 协议的程序。编写一个服务器端程序,该程序可接收多个客户端谜的请求。编写一个客户端程序,该程序可向服务器发送一些文本消息。服务器端程序需要使用多线程。 (2)使用UDP 协议,编写程序实现(1)的功能

1. 基于 TCP 协议的程序

服务器端程序：

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

public class TCPServer {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = new ServerSocket(8888);
        System.out.println("服务器已启动，等待客户端连接...");
        while (true) {
            Socket socket = serverSocket.accept();
            new Thread(new ServerThread(socket)).start();
        }
    }
}

class ServerThread implements Runnable {
    private Socket socket;

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

    @Override
    public void run() {
        try {
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
            String line;
            while ((line = in.readLine()) != null) {
                System.out.println("客户端发送的消息：" + line);
                out.println("服务器收到了你的消息：" + line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

客户端程序：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;

public class TCPClient {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket("localhost", 8888);
        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.print("请输入要发送的消息：");
            String line = scanner.nextLine();
            out.println(line);
            String response = in.readLine();
            System.out.println("服务器返回的消息：" + response);
        }
    }
}

2. 基于 UDP 协议的程序

服务器端程序：

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class UDPServer {
    public static void main(String[] args) throws IOException {
        DatagramSocket serverSocket = new DatagramSocket(8888);
        System.out.println("服务器已启动，等待客户端连接...");
        byte[] buffer = new byte[1024];
        while (true) {
            DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
            serverSocket.receive(packet);
            String message = new String(packet.getData(), 0, packet.getLength());
            System.out.println("客户端发送的消息：" + message);
            DatagramPacket response = new DatagramPacket(("服务器收到了你的消息：" + message).getBytes(),
                    ("服务器收到了你的消息：" + message).getBytes().length, packet.getAddress(), packet.getPort());
            serverSocket.send(response);
        }
    }
}

客户端程序：

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Scanner;

public class UDPClient {
    public static void main(String[] args) throws IOException {
        DatagramSocket socket = new DatagramSocket();
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.print("请输入要发送的消息：");
            String line = scanner.nextLine();
            byte[] data = line.getBytes();
            DatagramPacket packet = new DatagramPacket(data, data.length, InetAddress.getByName("localhost"), 8888);
            socket.send(packet);
            byte[] buffer = new byte[1024];
            DatagramPacket response = new DatagramPacket(buffer, buffer.length);
            socket.receive(response);
            String message = new String(response.getData(), 0, response.getLength());
            System.out.println("服务器返回的消息：" + message);
        }
    }
}