java 比较时间,DateDiff
之前是自己用 Calendar 类写,比较繁琐,也容易出错。在别人(项目经理)的推荐下,了解了一个专门的工具类
DateDiff
实现方式也是通过 Calendar 的方式
import java.util.Calendar; import java.util.Date; public class DateDiff { /** * 按指定日期单位计算两个日期间的间隔 * * @param timeInterval, * @param date1, * @param date2 * @return date1-date2, */ public static synchronized long dateDiff(String timeInterval, Date date1, Date date2) {
if (timeInterval.equals("year")) { Calendar calendar = Calendar.getInstance(); calendar.setTime(date1); int time = calendar.get(Calendar.YEAR); calendar.setTime(date2); return time - calendar.get(Calendar.YEAR); } if (timeInterval.equals("quarter")) { Calendar calendar = Calendar.getInstance(); calendar.setTime(date1); int time = calendar.get(Calendar.YEAR) * 4; calendar.setTime(date2); time -= calendar.get(Calendar.YEAR) * 4; calendar.setTime(date1); time += calendar.get(Calendar.MONTH) / 4; calendar.setTime(date2); return time - calendar.get(Calendar.MONTH) / 4; } if (timeInterval.equals("month")) { Calendar calendar = Calendar.getInstance(); calendar.setTime(date1); int time = calendar.get(Calendar.YEAR) * 12; calendar.setTime(date2); time -= calendar.get(Calendar.YEAR) * 12; calendar.setTime(date1); time += calendar.get(Calendar.MONTH); calendar.setTime(date2); return time - calendar.get(Calendar.MONTH); } if (timeInterval.equals("week")) { Calendar calendar = Calendar.getInstance(); calendar.setTime(date1); int time = calendar.get(Calendar.YEAR) * 52; calendar.setTime(date2); time -= calendar.get(Calendar.YEAR) * 52; calendar.setTime(date1); time += calendar.get(Calendar.WEEK_OF_YEAR); calendar.setTime(date2); return time - calendar.get(Calendar.WEEK_OF_YEAR); } if (timeInterval.equals("day")) { long time = date1.getTime() / 1000 / 60 / 60 / 24; return time - date2.getTime() / 1000 / 60 / 60 / 24; } if (timeInterval.equals("hour")) { long time = date1.getTime() / 1000 / 60 / 60; return time - date2.getTime() / 1000 / 60 / 60; } if (timeInterval.equals("minute")) { long time = date1.getTime() / 1000 / 60; return time - date2.getTime() / 1000 / 60; } if (timeInterval.equals("second")) { long time = date1.getTime() / 1000; return time - date2.getTime() / 1000; } return date1.getTime() - date2.getTime(); } }