clientservice.java

一个JAVA做的简单的聊天程序

import java.io.*;
import java.net.*;
public class ClientService
{
	public static void main(String args[])
	{
		DatagramSocket UDPClientSocket;
		DatagramPacket ClientPacket;
		InetAddress RemoteHost;
		int RemotePort;
		byte dataBuf[]=new byte[512];
		String Datagram,s;
		if(args.length<3)
		{
			System.out.println("请输入本地端口号，远程服务器主机名，服务器端口号");
			System.exit(0);
		}
		try{
  			UDPClientSocket=new DatagramSocket(Integer.parseInt(args[0]));
			RemoteHost=InetAddress.getByName(args[1]);
			RemotePort=Integer.parseInt(args[2]);
			Datagram=new String("This mail is from"+InetAddress.getLocalHost().getHostName()
			+",give me a receipt\n if you can receive it,Thank you!");
			Datagram.getBytes(0,Datagram.length(),dataBuf,0);
			ClientPacket=new DatagramPacket(dataBuf,512,RemoteHost,RemotePort);
			UDPClientSocket.send(ClientPacket);
			for(int i=0;i<512;i++) dataBuf[i]=0;
			UDPClientSocket.receive(ClientPacket);
			Datagram=new String(ClientPacket.getData());
			System.out.println("从远程服务器主机"+args[1]+"收到如下应答信息：");
			System.out.println(Datagram);
			UDPClientSocket.close();
		   }
		catch(Exception e){
			System.err.println(e);
		}
	}
}