Question

获取前一周的开始和结束日期最方便，最短的方法是什么？示例：今天是2011-10-12（输入数据），但我希望得到2011-10-03（周一上周的日期）和2011-10-09（周一的上周日期）。

Answer 1

这是另一个JodaTime解决方案。既然你似乎只想要Dates（不是时间戳），我会使用DateMidnight类：

final DateTime input = new DateTime();
System.out.println(input);
final DateMidnight startOfLastWeek = 
    new DateMidnight(input.minusWeeks(1).withDayOfWeek(DateTimeConstants.MONDAY));
System.out.println(startOfLastWeek);
final DateMidnight endOfLastWeek = startOfLastWeek.plusDays(6);
System.out.println(endOfLastWeek);

<强>输出：

2011-10-12T18:13:50.865+02:00
2011-10-03T00:00:00.000+02:00
2011-10-10T00:00:00.000+02:00

Answer 2

public static Calendar firstDayOfLastWeek(Calendar c) {
    c = (Calendar) c.clone();
    // last week
    c.add(Calendar.WEEK_OF_YEAR, -1);
    // first day
    c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
    return c;
}

public static Calendar lastDayOfLastWeek(Calendar c) {
    c = (Calendar) c.clone();
    // first day of this week
    c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
    // last day of previous week
    c.add(Calendar.DAY_OF_MONTH, -1);
    return c;
}

Answer 3

如果不涉及第三方图书馆，我会去@maerics回答。我必须用add（）方法替换roll（）方法，因为roll将保持更高的字段不变。例如，8月22日将从8月1日开始滚动-7天。注意月份保持不变。源代码如下。

public static Calendar[] getLastWeekBounds(Calendar c) {
  int cdow = c.get(Calendar.DAY_OF_WEEK);
  Calendar lastMon = (Calendar) c.clone();
  lastMon.add(Calendar.DATE, -7 - (cdow - Calendar.MONDAY));
  Calendar lastSun = (Calendar) lastMon.clone();
  lastSun.add(Calendar.DATE, 6);
  return new Calendar[] { lastMon, lastSun };
}

Answer 4

您可以使用带参数Calendar.DATE的{{3}}和当周某一天的偏移量：

public static Calendar[] getLastWeekBounds(Calendar c) {
  int cdow = c.get(Calendar.DAY_OF_WEEK);
  Calendar lastMon = (Calendar) c.clone();
  lastMon.roll(Calendar.DATE, -7 - (cdow - Calendar.MONDAY));
  Calendar lastSun = (Calendar) lastMon.clone();
  lastSun.roll(Calendar.DATE, 6);
  return new Calendar[] { lastMon, lastSun };
}

此函数返回两个日历的数组，第一个是上周的星期一和上周的星期日。

哇，Java日期API非常糟糕。

Answer 5

使用Joda：

DateTime input;
DateTime startOfLastWeek = input.minusWeeks(1).minusDays(input.getDayOfWeek()-1);

~~DateTime endOfLastWeek = input.minusWeeks（1）.plusDays（input.getDayOfWeek（）+ 1）;~~

DateTime endOfLastWeek = startOfLastWeek.plusDays(6);

编辑：

Joda does not allow a different first day of the week, but strictly sticks to the ISO standard, which states that a week always starts on Monday。但是，如果您需要进行可配置，则可以将所需的第一天作为参数传递。有关其他一些想法，请参阅上面的链接。

public DateTime getFirstDayOfPreviousWeek(DateTime input)
{
    return getFirstDayOfPreviousWeek(input, DateTimeConstants.MONDAY); 
}

public DateTime getFirstDayOfPreviousWeek(DateTime input, int firstDayOfWeek)
{
    return new DateTime(input.minusWeeks(1).withDayOfWeek(firstDayOfWeek));
}

public DateTime getLastDayOfPreviousWeek(DateTime input)
{
    return getLastDayOfPreviousWeek(input, DateTimeConstants.MONDAY); 
}

public DateTime getLastDayOfPreviousWeek(DateTime input, int firstDayOfWeek)
{
    return new DateTime(getFirstDayOfPreviousWeek(input, firstDayOfWeek).plusDays(6));
}

Answer 6

Calendar today  = Calendar.getInstance();
Calendar lastWeekSunday =  (today.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) ? today.roll(-7): today.roll(Calendar.DAY_OF_YEAR, Calendar.SUNDAY - today.get(Calendar.DAY_OF_WEEK));
Calendar lastWeekMonday = lastWeekSunday.roll( Calendar.DAY_OF_YEAR, -6 );

Java日历：计算上周的开始日期和结束日期

6 个答案: