package cn.sasa.netDemo2;

import java.io.IOException;

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.InetAddress;

import java.util.Scanner;

public class SendDemo {

    public static void main(String[] args) throws IOException {

        /**

         *

         */

        Scanner scanner = new Scanner(System.in);

        DatagramSocket socket = new DatagramSocket();//发送使用空参构造函数

        InetAddress host = InetAddress.getByName("127.0.0.1");

        while(true) {

            String input = scanner.nextLine();

            byte[] buff = input.getBytes();

            DatagramPacket packet = new DatagramPacket(buff, buff.length, host, 8046);

            socket.send(packet);//调用send

        }

    }

}

package cn.sasa.netDemo2;

import java.io.IOException;

import java.net.DatagramPacket;

import java.net.DatagramSocket;

public class ReceiveDemo {

    public static void main(String[] args) throws IOException {

        DatagramSocket socket = new DatagramSocket(8046);

        byte[] buff = new byte[1024];

        while(true) {

            DatagramPacket packet = new DatagramPacket(buff, buff.length);

            socket.receive(packet);

            int length = packet.getLength();//接收的字节长度

            System.out.println(new String(buff,0,length)+"==="+packet.getAddress().getHostAddress());

        }

    }

}