import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.InetAddress;

//=================================================

// File Name       :	UDPServer_demo

//------------------------------------------------------------------------------

// Author          :	Common

//主类

//Function        : 	UDPServer_demo

public class UDPServer_demo {

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

		// TODO 自动生成的方法存根

		DatagramSocket ds = null;					//声明DatagramSocket对象

		DatagramPacket dp = null;					//声明DatagramPacket对象

		ds = new DatagramSocket(3000);

		String str = "HelloWord";

		dp = new DatagramPacket(str.getBytes(),str.length(),InetAddress.getByName("localhost"),9000);

		System.out.println("发送信息");

		ds.send(dp);

		ds.close();

	}

}

import java.net.DatagramPacket;

import java.net.DatagramSocket;

//=================================================

// File Name       :	UDPClient_demo

//------------------------------------------------------------------------------

// Author          :	Common

//主类

//Function        : 	UDPClient_demo

public class UDPClient_demo {

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

		// TODO 自动生成的方法存根

		DatagramSocket ds = null;					//声明DatagramSocket对象

		byte[] buf = new byte[1024];			//定义接收数据的字节数据

		DatagramPacket dp = null;					//声明DatagramPacket对象

		ds = new DatagramSocket(9000);		//此客户端在9000端口监听

		dp = new DatagramPacket(buf,1024);			//指定接收数据的长度为1024

		System.out.println("等待接收数据");

		ds.receive(dp); 				//接收数据

		String str = new String(dp.getData(),0,dp.getLength())+" from"

		+dp.getAddress().getHostAddress()+" : "+dp.getPort();	//接收数据

		System.out.println(str);			//输出数据

		ds.close();

	}

}