Java TCP客户端示例

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

public class TCPClient {
    public static void main(String[] args) {
        try (
            Socket socket = new Socket("localhost", 12345);  // 连接服务端
            PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()))
        ) {
            // 发送数据
            out.println("Hello TCP Server!");
            
            // 接收响应
            String response = in.readLine();
            System.out.println("Server response: " + response);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Java UDP客户端示例

import java.net.*;

public class UDPClient {
    public static void main(String[] args) {
        try (DatagramSocket socket = new DatagramSocket()) {
            // 发送数据
            String message = "Hello UDP Server!";
            byte[] buffer = message.getBytes();
            InetAddress address = InetAddress.getByName("localhost");
            int port = 54321;
            DatagramPacket packet = new DatagramPacket(buffer, buffer.length, address, port);
            socket.send(packet);
            
            // 接收响应（可选）
            byte[] receiveBuffer = new byte[1024];
            DatagramPacket receivePacket = new DatagramPacket(receiveBuffer, receiveBuffer.length);
            socket.receive(receivePacket);
            System.out.println("Server response: " + new String(receivePacket.getData()));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

TCP与UDP对比表格

关键差异总结