Java 实现倒计时（由秒计算天、小时、分钟、秒）

有时候会要求实现这样一个需求：

天、小时、分钟、秒的数值都是隔开的，服务器端只返回一个时间戳长度。

以下就是我的实现方案，力求减少对象生成、减小计算量：

import java.util.Timer;
import java.util.TimerTask;

public class CountDownUtils {
	private static long day = 0;
	private static long hour = 0;
	private static long minute = 0;
	private static long second = 0;

	private static boolean dayNotAlready = false;
	private static boolean hourNotAlready = false;
	private static boolean minuteNotAlready = false;
	private static boolean secondNotAlready = false;

	public static void main(String[] args) {

		long totalSeconds = 60 * 60 * 24 * 34 + 21;
		initData(totalSeconds);

		new Timer().schedule(new TimerTask() {
			public void run() {
				if (secondNotAlready) {
					startCount();
				} else {
					cancel();
				}

			}
		}, 0, 1000);
	}

	/**
	 * 初始化赋值
	 * 
	 * @param totalSeconds
	 */
	private static void initData(long totalSeconds) {
		resetData();

		if (totalSeconds > 0) {
			secondNotAlready = true;
			second = totalSeconds;
			if (second >= 60) {
				minuteNotAlready = true;
				minute = second / 60;
				second = second % 60;
				if (minute >= 60) {
					hourNotAlready = true;
					hour = minute / 60;
					minute = minute % 60;
					if (hour > 24) {
						dayNotAlready = true;
						day = hour / 24;
						hour = hour % 24;
					}
				}
			}
		}

		System.out.println("初始格式化后——>" + day + "天" + hour + "小时" + minute
				+ "分钟" + second + "秒");
	}

	private static void resetData() {
		day = 0;
		hour = 0;
		minute = 0;
		second = 0;
		dayNotAlready = false;
		hourNotAlready = false;
		minuteNotAlready = false;
		secondNotAlready = false;
	}

	/**
	 * 计算各个值的变动
	 * 
	 */
	public static void startCount() {
		if (secondNotAlready) {
			if (second > 0) {
				second--;
				if (second == 0 && !minuteNotAlready) {
					secondNotAlready = false;
				}
			} else {
				if (minuteNotAlready) {
					if (minute > 0) {
						minute--;
						second = 59;
						if (minute == 0 && !hourNotAlready) {
							minuteNotAlready = false;
						}

					} else {
						if (hourNotAlready) {
							if (hour > 0) {
								hour--;
								minute = 59;
								second = 59;
								if (hour == 0 && !dayNotAlready) {
									hourNotAlready = false;
								}

							} else {
								if (dayNotAlready) {
									day--;
									hour = 23;
									minute = 59;
									second = 59;
									if (day == 0) {
										dayNotAlready = false;
									}

								}
							}
						}
					}

				}
			}

		}

		System.out.println("距离截止日期还有——>" + day + "天" + hour + "小时" + minute
				+ "分钟" + second + "秒");
	}

}