package com.taoge.socke;

import java.io.IOException;

import java.net.DatagramPacket;

import java.net.DatagramSocket;



public class UDPEchoServer {

	private static final int ECHOMAX=255;//max size of echo datagram

	

	public static void main(String[] args) throws IOException {

		/*

			if(args.length!=1){

				throw new IllegalArgumentException("Parameter(s):<Port>");

			}

		*/

		//int servPort=Integer.parseInt(args[0]);

		int servPort = 5555;

		

		//1.创建一个DatagramSocket实例，指定本地端口号，可以选择指定本地地址

		DatagramSocket socket=new DatagramSocket(servPort);

		DatagramPacket packet=new DatagramPacket(new byte[ECHOMAX],ECHOMAX);

		

		while(true){

			//2.使用DatagramSocket的receive方法来接收一个DatagramPacket实例。

			socket.receive(packet);

			System.out.println("Handling client at "+packet.getAddress().getHostAddress()+" on port "+packet.getPort());

			System.out.println("包的数据:" + new String(packet.getData()));

			socket.send(packet);

			packet.setLength(ECHOMAX);

			//socket.close();

		}

	}

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Net;

using System.Net.Sockets;



namespace ConsoleApplication1

{



    /**

     * C# 版本UDP客户端，用与连接Java服务器端发送数据。

     * */

    class Program

    {

       



        static void Main(string[] args)

        {

            int SenderPort = 5555;

            String host = "127.0.0.1";



            IPAddress ip = IPAddress.Parse(host);

            IPEndPoint ipepoit = new IPEndPoint(ip,SenderPort);



            UdpClient udpClient = new UdpClient(SenderPort);

            udpClient.Connect(ip,SenderPort);



            Byte[] sendByts = Encoding.ASCII.GetBytes("welcome to chengdu!!");



            //udpClient.Send(sendByts,sendByts.Length);

            udpClient.Send(sendByts, 255);

            //IPEndPoint RemoteIpEndPoint = new IPEndPoint(ip, 0);



            //Byte[] receiveBytes = udpClient.Receive(ref RemoteIpEndPoint);

            //string returnData = Encoding.ASCII.GetString(receiveBytes);



            //Console.WriteLine("This is the message you received " + returnData.ToString());