UDP

UDP

发短信：不用连接，需要知道对方的地址！

发送短信

package com.shushu.net1;
?
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
?
public class UdpClientDemo01 {
    public static void main(String[] args) throws Exception {
        //1.建立一个Socket
        DatagramSocket socket = new DatagramSocket();
?
        //2.建个包
        String msg = "你好啊！服务器。";
        InetAddress localhost = InetAddress.getByName("localhost");
        int port = 9090;
        //数据、数据的长度起始、发给谁
        DatagramPacket packet = new DatagramPacket(msg.getBytes(),msg.getBytes().length,localhost,port);
?
        //3.发送包
        socket.send(packet);
        //4.关闭流
        socket.close();
?
    }
}

接收信息

package com.shushu.net1;
?
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
?
public class UdpServerDemo01 {
    public static void main(String[] args) throws Exception {
        //开放端口
        DatagramSocket socket = new DatagramSocket(9090);
        //接收数据包
        byte[] buffer = new byte[1024];
        DatagramPacket packet = new DatagramPacket(buffer,0,buffer.length);
?
        socket.receive(packet);//阻塞接收
?
        System.out.println(packet.getAddress().getHostAddress());
        System.out.println(new String(packet.getData(),0,packet.getLength()));
?
        //关闭连接
        socket.close();
    }
}

UDP

原文：https://www.cnblogs.com/changhanbing/p/14720066.html