Java UDP套接字编程（一）简单发送与接收

Java UDP套接字编程（一）简单发送与接收

发送消息

package com.zzz.net;

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

public class UdpClientDemo01 {
    public static void main(String[] args) throws Exception {
        DatagramSocket socket = new DatagramSocket();   //建立一个socket

        String msg = "你好呀！";        //建个包，包含数据、起始、长度、目的IP、端口号
        DatagramPacket packet = new DatagramPacket(msg.getBytes(),0,msg.getBytes().length, InetAddress.getByName("localhost"),9090);

        socket.send(packet);    //发送包

        socket.close();     //关闭流
    }
}

接收消息

package com.zzz.net;

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

public class UdpServerDemo01 {
    public static void main(String[] args) throws Exception {
        DatagramSocket socket = new DatagramSocket(9090);   //建立一个socket

        byte[] buffer = new byte[1024];     //建个空包，用于接收
        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()));

        socket.close(); //关闭流
    }
}