UDP即时小通信

package 第十二章;

import java.io.IOException;
import java.net.*;

public class UDPServer {
	/***
	 *
	 * @param args
	 * @throws IOException
	 */
	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub

		System.out.println("服务器开启成功");
		DatagramSocket socket=new DatagramSocket(55555);

		while(true){
			byte[]b=new byte[1024];
//			UDP以数据包的形式发送
			DatagramPacket packet=new DatagramPacket(b,b.length);
			socket.receive(packet);

			String s=new String(packet.getData(),0,packet.getLength());
//			获得到发送端的IP
			String ip=packet.getAddress().toString();

			System.out.println(ip+":"+s);

		}

	}

}
//客户端

ackage 第十二章;
import java.io.IOException;
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 java.util.Scanner;

public class UDPClient {
	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		while(true){
			Scanner scan=new Scanner(System.in);
			System.out.println("请输入要发送的数据");
			String str =new String();
			str=scan.nextLine();
			byte[]b=str.getBytes();
//			服务器端的IP地址
			InetAddress serverAddress=InetAddress.getByName("192.168.1.179");
//			参数列表：字节数组，数组的长度，服务器的IP地址，服务器的端口号
			DatagramPacket packet=new DatagramPacket(b,b.length,serverAddress,55555);

//			DatagramSocket可以将这个数据包发送到服务器
			DatagramSocket socket=new DatagramSocket();
			socket.send(packet);
		}

	}

}