UDP 通信

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;


public class UDPsend {

	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception {
		// TODO Auto-generated method stub
		DatagramSocket ds=new DatagramSocket();
		String string="hello world";
		DatagramPacket dp=new DatagramPacket(string.getBytes(), string.length(),InetAddress.getByName("127.0.0.1"),4321);
		ds.send(dp);
		ds.close();
	}
}

 

import java.net.DatagramPacket;
import java.net.DatagramSocket;


public class UDPrecv {

	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception {
		// TODO Auto-generated method stub
		DatagramSocket ds=new DatagramSocket(4321);
		byte[] buf=new byte[1024];
		DatagramPacket dp=new DatagramPacket(buf, 1024);
		ds.receive(dp);
		String strRecv=new String(dp.getData(),0,dp.getLength())+"from"+dp.getAddress().getHostAddress()+":"+dp.getPort();
		System.out.println(strRecv);
		ds.close();
	}

}