UDP的使用方法

/*

 * 如果IP的最后一个段为255则表示为广播，可以使所有的局域网用户接收到广播

 */

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.InetAddress;

public class UDPSendReceiveDemo {

public static void main(String[] args)throws Exception {
DatagramSocket ds=new DatagramSocket();
BufferedReader bufr=new BufferedReader(new InputStreamReader(System.in));
String  line=null;
while ((line=bufr.readLine())!=null) {
if ("886".equals(line)) {
break;

}
byte[]buf=line.getBytes();
DatagramPacket dp=new DatagramPacket(buf, buf.length,InetAddress.getByName("127.0.0.1"),8888);
}

ds.close();

}

}

/*

 * 接收端

 */

class UDPReceive2{
public static void main(String[] args) throws Exception{
DatagramSocket ds=new DatagramSocket();
while (true) {
byte[]buf=new byte[1024];
DatagramPacket dp=new DatagramPacket(buf, buf.length);

ds.receive(dp);

String ip=dp.getAddress().getHostAddress();
String data=new String(dp.getData(), 0, dp.getLength());
System.out.println(ip+"::::"+data);
}

}

}