16周udp

//发送端import java.net.*;public class TheSender {    public static void main(String[] args) throws Exception{        DatagramSocket ds=new DatagramSocket(3000);        String str="Hello,world";        DatagramPacket dp=new DatagramPacket(str.getBytes(),str.length(),                InetAddress.getByName("localhost"),8001);        System.out.println("发送信息");        ds.send(dp);        ds.close();    }}

//接收端import java.net.*;public class TheReceivingEnd {    public static void main(String[] args) throws Exception{        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()) +"   from   "         + dp.getAddress().getHostAddress() + " : " + dp.getPort();        System.out.println(str);        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”。 */