当前月份的开始日期和结束日期

date-manipulation java

2022-09-01 00:41:25

我需要Java中当前月份的开始日期和结束日期。当 JSP 页面加载当前月份时，它应自动计算该月的开始日期和结束日期。它应该与年份和月份无关。也就是说，某个月份有31天或30天或28天。这也应该满足闰年。你能帮我吗？

例如，如果我在列表框中选择“月 5 月”，我需要开始日期为 1，结束日期为 31。

答案 1

给你：

public Pair<Date, Date> getDateRange() {
    Date begining, end;

    {
        Calendar calendar = getCalendarForNow();
        calendar.set(Calendar.DAY_OF_MONTH,
                calendar.getActualMinimum(Calendar.DAY_OF_MONTH));
        setTimeToBeginningOfDay(calendar);
        begining = calendar.getTime();
    }

    {
        Calendar calendar = getCalendarForNow();
        calendar.set(Calendar.DAY_OF_MONTH,
                calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
        setTimeToEndofDay(calendar);
        end = calendar.getTime();
    }

    return Pair.of(begining, end);
}

private static Calendar getCalendarForNow() {
    Calendar calendar = GregorianCalendar.getInstance();
    calendar.setTime(new Date());
    return calendar;
}

private static void setTimeToBeginningOfDay(Calendar calendar) {
    calendar.set(Calendar.HOUR_OF_DAY, 0);
    calendar.set(Calendar.MINUTE, 0);
    calendar.set(Calendar.SECOND, 0);
    calendar.set(Calendar.MILLISECOND, 0);
}

private static void setTimeToEndofDay(Calendar calendar) {
    calendar.set(Calendar.HOUR_OF_DAY, 23);
    calendar.set(Calendar.MINUTE, 59);
    calendar.set(Calendar.SECOND, 59);
    calendar.set(Calendar.MILLISECOND, 999);
}

PS：类只是两个值的对。Pair

答案 2

如果你有这个选项，你最好避免可怕的Java Date API，而是使用Jodatime。下面是一个示例：

LocalDate monthBegin = new LocalDate().withDayOfMonth(1);
LocalDate monthEnd = new LocalDate().plusMonths(1).withDayOfMonth(1).minusDays(1);