java倒计时

import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.Scanner;
import java.util.Timer;
import java.util.TimerTask;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class CountDown extends TimerTask {
	private static long targetInMill;
	private static boolean flag = true;
	private static Timer timer;

	public static void main(String[] args) {
		init();
		CountDown cd = new CountDown();
		long delay = 1000;
		timer = new Timer();
		timer.schedule(cd, 0, delay);
	}

	// 设定目标时间
	private static void init() {
		Scanner sc = new Scanner(System.in);
		try {
			//输入时间
			String targetTime = sc.nextLine();
			//验证时间
			Pattern p = Pattern
					.compile("^(19|20)\\d\\d[-/.]((0[1-9])|([1-9])|(1[0-2]))[-/.](([0-2][1-9])|([1-2]0)|(3[0-1])|([1-9])) (([0-1]\\d)|([1-9])|(2[0-3]|(0))):(([0-5]\\d)|([1-9])):(([0-5]\\d)|([1-9]))$");
			Matcher m = p.matcher(targetTime);
			if (!m.matches()) {
				throw new Exception("输入日期格式不对");
			}
			
			int year, month, day, hour, minute, second;

			String date = targetTime.split(" ")[0];
			String time = targetTime.split(" ")[1];

			year = Integer.valueOf(date.split("-")[0]);
			month = Integer.valueOf(date.split("-")[1]);
			day = Integer.valueOf(date.split("-")[2]);

			hour = Integer.valueOf(time.split(":")[0]);
			minute = Integer.valueOf(time.split(":")[1]);
			second = Integer.valueOf(time.split(":")[2]);

			Calendar target = new GregorianCalendar(year, month - 1, day, hour,
					minute, second);
			//将目标时间化成毫秒
			targetInMill = target.getTimeInMillis();
			
		} catch (Exception e) {
			e.printStackTrace();
			System.err.println(e.toString());
		}
	}

	// 开始计时
	public void run() {
		try {
			Calendar today = new GregorianCalendar();
			//将当前时间化成毫秒
			long todayInMill = today.getTimeInMillis();
			//获取时间差
			long dd = targetInMill - todayInMill;
			//将当前时间化成毫秒
			long dis = dd / 1000;

			String d;
			int day = (int) (dis / (3600 * 24));
			int hour = (int) (dis % (3600 * 24) / 3600);
			int min = (int) (dis % 3600 / 60);
			int sec = (int) (dis % 60);
			if (day < 10)
				d = " " + day;
			else if (day >= 10 && day < 100)
				d = " " + day;
			else
				d = day + "";
			String s = d + " 天 " + Integer.valueOf(hour) + " 小时 "
					+ Integer.valueOf(min) + " 分 " + Integer.valueOf(sec)
					+ " 秒";
			System.out.println(s);
			//如果时间差是负值，则计数器关闭
			if (dd <= 0) {
				System.out.println("时间到");
				flag = false;
			}
		} catch (Exception e) {
			System.err.println(e.toString());
		}finally{
			while(!flag){
				timer.cancel();
			}
		}
	}
}