import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.Socket;
import java.net.SocketException;
import java.net.UnknownHostException;

import org.junit.Test;

public class TestUDP {

	@Test
	public void send() throws Exception{
		String str = "Hello";
		DatagramPacket pack = new DatagramPacket(str.getBytes(),str.getBytes().length,InetAddress.getByName("127.0.0.1"),10000);
	    
		DatagramSocket scoket = new DatagramSocket();
		for(int i =0; i< 10;i++){
			scoket.send(pack);
		}
		
		
		scoket.close();
	}
	
	@Test
	public void revice() throws Exception{
		
		byte[] by = new byte[1024];

		DatagramPacket pack = new DatagramPacket(by,by.length);
		
		DatagramSocket scoket = new DatagramSocket(10000);
		while(true){
			scoket.receive(pack);
			
			System.out.println(new String(pack.getData()));
			
		}
		
	}

}

java之UDP(datagramsocket,datagramPacket)实例