Calculate days between two dates in Java 8
我知道有很多关于如何获得的问题,但我想要和使用新的Java 8 Date api的例子。 我也知道JodaTime库,但我想要一种没有外部库的工作方式。
功能需要抱怨这些限制:
如果您想要逻辑日历日,请使用
1 2 3 | LocalDate dateBefore; LocalDate dateAfter; long daysBetween = DAYS.between(dateBefore, dateAfter); |
如果你想要文字24小时日(持续时间),你可以使用
1 2 3 4 | LocalDate today = LocalDate.now() LocalDate yesterday = today.minusDays(1); // Duration oneDay = Duration.between(today, yesterday); // throws an exception Duration.between(today.atStartOfDay(), yesterday.atStartOfDay()).toDays() // another option |
有关更多信息,请参阅此文档(以及其他文档:Oracle的Java 8)。
根据VGR的评论,您可以使用以下内容:
1 | ChronoUnit.DAYS.between(firstDate, secondDate) |
您可以使用
1 2 3 4 5 | LocalDate independenceDay = LocalDate.of(2014, Month.JULY, 4); LocalDate christmas = LocalDate.of(2014, Month.DECEMBER, 25); System.out.println("Until christmas:" + independenceDay.until(christmas)); System.out.println("Until christmas (with crono):" + independenceDay.until(christmas, ChronoUnit.DAYS)); |
您可以使用
例如
1 2 3 4 5 | import java.time.temporal.ChronoUnit; public long getDaysCountBetweenDates(LocalDate dateBefore, LocalDate dateAfter) { return DAYS.between(dateBefore, dateAfter); } |
If starDate and endDate are instance of java.util.Date, besides to
@mohamed answer
1 |
但ChronoUnit.DAYS计算完成24小时的天数。
每个人都说使用ChronoUnit.DAYS.between,但只是委托给你自己称之为另一种方法。所以你也可以做
两者的文档实际上都提到了这两种方法,并说使用哪一种更具可读性。
在枚举java.time.temporal.ChronoUnit中使用DAYS。以下是示例代码:
输出:
*开始日期:2015-03-01和结束日期之间的天数:2016-03-03是==> 368。
**开始日期:2016-03-03和结束日期之间的天数:2015-03-01是==> -368 *
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | package com.bitiknow.date; import java.time.LocalDate; import java.time.temporal.ChronoUnit; /** * * @author pradeep * */ public class LocalDateTimeTry { public static void main(String[] args) { // Date in String format. String dateString ="2015-03-01"; // Converting date to Java8 Local date LocalDate startDate = LocalDate.parse(dateString); LocalDate endtDate = LocalDate.now(); // Range = End date - Start date Long range = ChronoUnit.DAYS.between(startDate, endtDate); System.out.println("Number of days between the start date :" + dateString +" and end date :" + endtDate +" is ==>" + range); range = ChronoUnit.DAYS.between(endtDate, startDate); System.out.println("Number of days between the start date :" + endtDate +" and end date :" + dateString +" is ==>" + range); } } |
干得好:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | public class DemoDate { public static void main(String[] args) { LocalDate today = LocalDate.now(); System.out.println("Current date:" + today); //add 1 month to the current date LocalDate date2 = today.plus(1, ChronoUnit.MONTHS); System.out.println("Next month:" + date2); // Put latest date 1st and old date 2nd in 'between' method to get -ve date difference long daysNegative = ChronoUnit.DAYS.between(date2, today); System.out.println("Days :"+daysNegative); // Put old date 1st and new date 2nd in 'between' method to get +ve date difference long datePositive = ChronoUnit.DAYS.between(today, date2); System.out.println("Days :"+datePositive); } } |
获取当天圣诞节前的天数,试试这个
1 | System.out.println(ChronoUnit.DAYS.between(LocalDate.now(),LocalDate.of(Year.now().getValue(), Month.DECEMBER, 25))); |
如果目标只是为了获得天数的差异,并且由于上述答案提到了委托方法,我想指出一次也可以简单地使用 -
1 2 3 4 5 | public long daysInBetween(java.time.LocalDate startDate, java.time.LocalDate endDate) { // Check for null values here return endDate.toEpochDay() - startDate.toEpochDay(); } |
get days between two dates date is instance of java.util.Date
1 2 3 |
我知道这个问题适用于Java 8,但使用Java 9可以使用:
1 2 3 4 | public static List<LocalDate> getDatesBetween(LocalDate startDate, LocalDate endDate) { return startDate.datesUntil(endDate) .collect(Collectors.toList()); } |