利用Java获取网络标准时间

import java.net.*;
import java.io.*;
public class DaytimeClient
{
	/**
	 * @param args
	 */
	public static void main(String[] args)
	{
		// TODO Auto-generated method stub
		String[] hostname = new String[]{"", "time.windows.com","time.nist.gov","time-nw.nist.gov","time-a.nist.gov","time-b.nist.gov"};
		int i = 1;
		boolean RecvFlag = false;
		if(args.length > 0)
		{
			hostname[0] = args[0];
			i = 0;
		}
		while(i <=5 && !RecvFlag)
		{
			try
			{
				Socket timeSocket = new Socket(hostname[i], 13);
				InputStream timeStream = timeSocket.getInputStream();
				StringBuffer time = new StringBuffer();
				int c;
				while((c=timeStream.read()) != -1)
					time.append((char)c);
				String timeString = time.toString().trim();
				System.out.println("It is " + timeString +" at " + hostname[i] +" on port " + timeSocket.getPort());
				RecvFlag = true;
				timeSocket.close();
			}
			catch(UnknownHostException e)
			{
				System.out.println("Failed to get the information from " + hostname[i]);
				System.out.println(e);
				i++;
			}
			catch(Exception e)
			{
				System.out.println("Failed to get the information from " + hostname[i]);
				System.out.println(e);
				i++;
			}
		}
		if(i == 6)
			System.out.println("Failed to get the information please check your network settings.");
		else
			System.out.println("Complete.");
	}
}