udp

package udp;import java.net.DatagramPacket;import java.net.DatagramSocket;public class Udp {    public static void main(String[] args) throws Exception {        // TODO Auto-generated method stub        byte[] buf=new byte[1024];        DatagramSocket ds=new DatagramSocket(8001);        DatagramPacket dp=new DatagramPacket(buf, 1024);        System.out.println("等待接收数据");        ds.receive(dp);        String str=new String(dp.getData(),0,dp.getLength());        System.out.println(str);        ds.close();    }}package javasocket;import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.InetAddress;public class UDPclient {    public static void main(String[] args) throws Exception {        // TODO Auto-generated method stub        DatagramSocket ds=new DatagramSocket(8009);        String str="hello world";        DatagramPacket dp=new DatagramPacket(str.getBytes(),str.length(),InetAddress.getByName("localhost"),8001);        ds.send(dp);        ds.close();    }}

使用UDP协议编写一个网络程序，设置接收端程序的监听端口是8001，发送端发送的数据是“Hello, world”。