java - 获取 2 个日期之间的周数，其中周数跨越 2 个月

Question

我想获取 2 个日期之间的所有周，其中跨 2 个月的周每个月计算两次。例如，2021 年的第 14 周同时举办了 3 月和 4 月，因此在这种情况下，我希望该周计算两次(一次为 3 月，一次为 4 月)。我查看并发现只有一些库可以计算两个日期之间的周数。我想我可以得到周数和月份数并形成一个独特的数组，但这似乎有点过头了。有人有什么建议吗？

Answer 1

weeks that cross 2 months counted twice

下面的代码允许仅使用标准 LocalDate 类及其方法 isBefore()、plusWeeks()、plusDays().

请记住，星期几和月份由java.time中的枚举表示包。

我做了一些假设:

• 一周从星期日开始；
• 必须考虑给定期间开始和结束的一周中的部分内容以及完整的周。

    public static void main(String[] args) {
        System.out.println(getWeekCount(LocalDate.of(2022, 1, 1),
                                        LocalDate.of(2022, 2, 1)));

        System.out.println(getWeekCount(LocalDate.of(2022, 1, 1),
                                        LocalDate.of(2022, 3, 1)));
    }

    public static int getWeekCount(LocalDate date1, LocalDate date2) {
        int weekCount = 0;
        LocalDate cur = date1;
        LocalDate finish = date2;
        // assumption: week starts with sunday
        // assumption: chunk of week at the start and at the end have to be taken into account as well as full weeks
        if (cur.getDayOfWeek() != DayOfWeek.SUNDAY) { // adjusting current date
            LocalDate next = cur.plusDays(DayOfWeek.SUNDAY.ordinal() - cur.getDayOfWeek().ordinal() + 1);
            weekCount += getWeeksIncrement(cur, next);
            cur = next;
        }
        if (finish.getDayOfWeek() != DayOfWeek.SUNDAY) { // adjusting finish date
            LocalDate previous = finish.minusDays(finish.getDayOfWeek().ordinal() + 1);
            weekCount += getWeeksIncrement(previous, finish);
            finish = previous;
        }
        while (cur.isBefore(finish) || cur.equals(finish)) {
            LocalDate next = cur.plusWeeks(1);
            weekCount += getWeeksIncrement(cur, next);
            cur = next;
        }
        return weekCount;
    }

    public static int getWeeksIncrement(LocalDate cur, LocalDate next) {
        return weekIsSharedBetweenTwoMonth(cur, next) ? 2 : 1;
    }

    public static boolean weekIsSharedBetweenTwoMonth(LocalDate cur, LocalDate next) {
        return next.getMonth() != cur.getMonth() &&
                next.withDayOfMonth(1).isAfter(cur);
    }

输出

7   -  weeks between: 2022-01-01 and 2022-02-01
12  -  weeks between: 2022-01-01 and 2022-03-01