UDP

UDP

发送端

1. 构建socket
2. 构建发送的数据包
3. 发送数据报
4. 关闭socket

import java.io.InputStream;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;

public class UDPClient {
    public static void main(String[] args) throws Exception {
        //1.构建socket
        DatagramSocket socket = new DatagramSocket();
        //2.构建发送的数据包
        String msg = "Hello, Server!";
        InetAddress localhost = InetAddress.getByName("localhost");
        int post = 9090;
        DatagramPacket packet = new DatagramPacket(msg.getBytes(), 0 ,msg.getBytes().length, localhost,post);
        //3.发送数据报
        socket.send(packet);
        //4.关闭socket
        socket.close();
    }
}

接收端

1. 开放端口
2. 接收数据报
3. 输出packet数据
4. 关闭socket

import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class UDPServer {
    public static void main(String[] args) throws Exception{
        //1.开放端口
        DatagramSocket socket = new DatagramSocket(9090);
        //2.接收数据包
        byte[] buffer = new byte[1024];
        DatagramPacket packet = new DatagramPacket(buffer,0,buffer.length);
        socket.receive(packet);
        //3.输出packet数据
        System.out.println(packet.getAddress().getHostAddress());
        System.out.println(new String(packet.getData(),0,packet.getLength()));
        //4.关闭socket
        socket.close();

    }
}

结果：