Java Joda Time Minus Weeks（）和plusweeks（）的2014/2015年年假细分？

我可能在这里遗漏了一些东西，但我似乎无法在Joda Time的文档或任何地方找到解释。当你从一年到下一年计算周数时，加减周数时，Joda Time似乎会崩溃

有人能解释为什么会发生这种情况以及如何正确地做到这一点吗

我从下面的代码中获得以下输出：

2015-01-08 - This is the current week
2015-01-01 - Removed one week
2014-12-25 - Removed one week
2014-12-17 - Removed one week //for some reason, program backed 8 days here
2014-12-10 - Removed one week
2014-12-17 - Added one week
2014-12-24 - Added one week
2014-12-31 - Added one week
2014-01-08 - Added one week //for some reason, program forwarded 8 days here, but it did not forward to 2015.

原始代码

import org.joda.time.*;

public class WonkyWeeks {
    int year;
    int week;

    public void backUpOneWeek() {
        LocalDate today = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        LocalDate lastWeek = today.minusWeeks(1);

        week = lastWeek.getWeekOfWeekyear();
        year = lastWeek.getYear();
        System.out.println(lastWeek+" - Removed one week");
    }

    public void forwardOneWeek() {
        LocalDate today = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        LocalDate nextWeek = today.plusWeeks(1);

        week = nextWeek.getWeekOfWeekyear();
        year = nextWeek.getYear();
        System.out.println(nextWeek+" - Added one week");
    }

    public void thisWeek() {
        LocalDate thisWeek = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        System.out.println(thisWeek+" - This is the current week");
    }

    public static void main(String[] args) {
        WonkyWeeks wonky = new WonkyWeeks();
        wonky.week = 2;
        wonky.year = 2015;
        wonky.thisWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
    }
}

import org.joda.time.*;

public class WonkyWeeks {
    int year;
    int week;

    public void backUpOneWeek() {
        LocalDate today = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        LocalDate adayago = today.minusDays(1);
        System.out.println(adayago+" - removed one day");
        LocalDate twodaysago = adayago.minusDays(1);
        System.out.println(twodaysago+" - removed one day");
        LocalDate threedaysago = twodaysago.minusDays(1);
        System.out.println(threedaysago+" - removed one day");
        LocalDate fourdaysago = threedaysago.minusDays(1);
        System.out.println(fourdaysago+" - removed one day");
        LocalDate fivedaysago = fourdaysago.minusDays(1);
        System.out.println(fivedaysago+" - removed one day");
        LocalDate sixdaysago = fivedaysago.minusDays(1);
        System.out.println(sixdaysago+" - removed one day");
        LocalDate lastWeek = sixdaysago.minusDays(1);

        week = lastWeek.getWeekOfWeekyear();
        year = lastWeek.getYear();
        System.out.println(lastWeek+" - Removed one full week");
    }
    public void forwardOneWeek() {
        LocalDate today = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        LocalDate tomorrow = today.plusDays(1);
        System.out.println(tomorrow+" - added one day");
        LocalDate dayAfterTomorrow = tomorrow.plusDays(1);
        System.out.println(dayAfterTomorrow+" - added one day");
        LocalDate threeDaysFromNow = dayAfterTomorrow.plusDays(1);
        System.out.println(threeDaysFromNow+" - added one day");
        LocalDate fourDaysFromNow = threeDaysFromNow.plusDays(1);
        System.out.println(fourDaysFromNow+" - added one day");
        LocalDate fiveDaysFromNow = fourDaysFromNow.plusDays(1);
        System.out.println(fiveDaysFromNow+" - added one day");
        LocalDate sixDaysFromNow = fiveDaysFromNow.plusDays(1);
        System.out.println(sixDaysFromNow+" - added one day");
        LocalDate nextWeek = sixDaysFromNow.plusDays(1);

        week = nextWeek.getWeekOfWeekyear();
        year = nextWeek.getYear();
        System.out.println(nextWeek+" - Added one week");
    }
    public void thisWeek() {
        LocalDate thisWeek = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        System.out.println(thisWeek+" - This is the current week");
    }
    public static void main(String[] args) {
        WonkyWeeks wonky = new WonkyWeeks();
        wonky.week = 2;
        wonky.year = 2015;
        wonky.thisWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
    }
}

经过进一步的测试，它变得更加混乱。我试着只添加和删除几天而不是几周，出于某种原因，它似乎跳过了日期

输出：

2015-01-08 - This is the current week
2015-01-07 - removed one day
2015-01-06 - removed one day
2015-01-05 - removed one day
2015-01-04 - removed one day
2015-01-03 - removed one day
2015-01-02 - removed one day
2015-01-01 - Removed one full week
2014-12-31 - removed one day
2014-12-30 - removed one day
2014-12-29 - removed one day
2014-12-28 - removed one day
2014-12-27 - removed one day
2014-12-26 - removed one day
2014-12-25 - Removed one full week
2014-12-23 - removed one day // For some reason, it skipped 2014-12-24?
2014-12-22 - removed one day
2014-12-21 - removed one day
2014-12-20 - removed one day
2014-12-19 - removed one day
2014-12-18 - removed one day
2014-12-17 - Removed one full week
2014-12-16 - removed one day
2014-12-15 - removed one day
2014-12-14 - removed one day
2014-12-13 - removed one day
2014-12-12 - removed one day
2014-12-11 - removed one day
2014-12-10 - Removed one full week
2014-12-11 - added one day
2014-12-12 - added one day
2014-12-13 - added one day
2014-12-14 - added one day
2014-12-15 - added one day
2014-12-16 - added one day
2014-12-17 - Added one week
2014-12-18 - added one day
2014-12-19 - added one day
2014-12-20 - added one day
2014-12-21 - added one day
2014-12-22 - added one day
2014-12-23 - added one day
2014-12-24 - Added one week
2014-12-25 - added one day
2014-12-26 - added one day
2014-12-27 - added one day
2014-12-28 - added one day
2014-12-29 - added one day
2014-12-30 - added one day
2014-12-31 - Added one week
2014-01-02 - added one day //Skipped 2014-01-01 and did not forward to 2015
2014-01-03 - added one day
2014-01-04 - added one day
2014-01-05 - added one day
2014-01-06 - added one day
2014-01-07 - added one day
2014-01-08 - Added one week

进一步测试代码

import org.joda.time.*;

public class WonkyWeeks {
    int year;
    int week;

    public void backUpOneWeek() {
        LocalDate today = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        LocalDate lastWeek = today.minusWeeks(1);

        week = lastWeek.getWeekOfWeekyear();
        year = lastWeek.getYear();
        System.out.println(lastWeek+" - Removed one week");
    }

    public void forwardOneWeek() {
        LocalDate today = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        LocalDate nextWeek = today.plusWeeks(1);

        week = nextWeek.getWeekOfWeekyear();
        year = nextWeek.getYear();
        System.out.println(nextWeek+" - Added one week");
    }

    public void thisWeek() {
        LocalDate thisWeek = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        System.out.println(thisWeek+" - This is the current week");
    }

    public static void main(String[] args) {
        WonkyWeeks wonky = new WonkyWeeks();
        wonky.week = 2;
        wonky.year = 2015;
        wonky.thisWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
    }
}

import org.joda.time.*;

public class WonkyWeeks {
    int year;
    int week;

    public void backUpOneWeek() {
        LocalDate today = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        LocalDate adayago = today.minusDays(1);
        System.out.println(adayago+" - removed one day");
        LocalDate twodaysago = adayago.minusDays(1);
        System.out.println(twodaysago+" - removed one day");
        LocalDate threedaysago = twodaysago.minusDays(1);
        System.out.println(threedaysago+" - removed one day");
        LocalDate fourdaysago = threedaysago.minusDays(1);
        System.out.println(fourdaysago+" - removed one day");
        LocalDate fivedaysago = fourdaysago.minusDays(1);
        System.out.println(fivedaysago+" - removed one day");
        LocalDate sixdaysago = fivedaysago.minusDays(1);
        System.out.println(sixdaysago+" - removed one day");
        LocalDate lastWeek = sixdaysago.minusDays(1);

        week = lastWeek.getWeekOfWeekyear();
        year = lastWeek.getYear();
        System.out.println(lastWeek+" - Removed one full week");
    }
    public void forwardOneWeek() {
        LocalDate today = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        LocalDate tomorrow = today.plusDays(1);
        System.out.println(tomorrow+" - added one day");
        LocalDate dayAfterTomorrow = tomorrow.plusDays(1);
        System.out.println(dayAfterTomorrow+" - added one day");
        LocalDate threeDaysFromNow = dayAfterTomorrow.plusDays(1);
        System.out.println(threeDaysFromNow+" - added one day");
        LocalDate fourDaysFromNow = threeDaysFromNow.plusDays(1);
        System.out.println(fourDaysFromNow+" - added one day");
        LocalDate fiveDaysFromNow = fourDaysFromNow.plusDays(1);
        System.out.println(fiveDaysFromNow+" - added one day");
        LocalDate sixDaysFromNow = fiveDaysFromNow.plusDays(1);
        System.out.println(sixDaysFromNow+" - added one day");
        LocalDate nextWeek = sixDaysFromNow.plusDays(1);

        week = nextWeek.getWeekOfWeekyear();
        year = nextWeek.getYear();
        System.out.println(nextWeek+" - Added one week");
    }
    public void thisWeek() {
        LocalDate thisWeek = new LocalDate()
                .withDayOfWeek(4)
                .withWeekOfWeekyear(week)
                .withYear(year);
        System.out.println(thisWeek+" - This is the current week");
    }
    public static void main(String[] args) {
        WonkyWeeks wonky = new WonkyWeeks();
        wonky.week = 2;
        wonky.year = 2015;
        wonky.thisWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
    }
}

---

我看你的逻辑没有问题。在尝试了不同的场景并调试了一些代码之后，我相信这是由于不同年份的

dayOfWeek

的行为造成的

这可能无法为您的问题提供完整的答案，但可能会给您一个提示

无论是哪一年，您都会通过一周中的第四天。但它代表不同的日子，取决于年份。 例如，如果您将第1周和2013年的

天设为4，然后调用
getDayOfWeek（）
，您将得到值为
2
（星期二）

同样，2014年的
getDayOfWeek（）
将返回
3
（星期三），2015年的
4
（星期四）

因此，对于2015年，第4周的一天代表周四，而对于2014年，它代表周三

现在让我们看看您的用例：


2015-01-08-这是本周（第2周，第4天-周四）
2015-01-01-删除一周-（第1周，第4天-周四）
2014年12月25日-删除一周-（第4周，第4天-周四）
2014年12月17日-删除一周-（此处更正-第3周，第2天）
第四-周三）

我不确定为什么没有在
2014-12-25
上进行更正。Joda时间是正确的，但不是您的逻辑。您必须仔细区分“日历年”（从1月1日开始）和周日期的年份（定义见ISO-8601，也称为“基于周的年”或简称“周年”）

例如，您在类中使用两个彼此不严格相关的成员来存储中间结果：

week = nextWeek.getWeekOfWeekyear();
year = nextWeek.getYear();

这些行的问题在于周与基于周的年份相关，而不是与第二行所示的日历年相关。请记住，基于周的年份可以比1月1日的日历年少一年。例如[2014-12-31]与[2015-W01-3]的日期相同。还要记住，Joda Time提供了另一种方法，称为
getWeekyear（）

然后，您将使用这两个值以这种方式操纵日期：

LocalDate today = new LocalDate()
        .withDayOfWeek(4)
        .withWeekOfWeekyear(week)
        .withYear(year);

同样的术语问题。当试图在当前周年2015年内保留周日时，
withWeekOfWeekyear（week）
方法已经可以更改日历年并将月日移到另一天，而不是2014日历年产生意外的日期移动！整个代码产生的结果不是真正可预测的，会让每个人都感到惊讶。另一个大问题是方法调用的顺序，这很重要，因为周操作指的是当前的周年（哪一个？！）。以下代码看起来更健康：

LocalDate today = new LocalDate()
        .withWeekyear(year)
        .withWeekOfWeekyear(week)
        .withDayOfWeek(4);

解决方案：您最好在代码中引用周年，而不是日历年。或者更好：如果您只是想添加或删除周，那么我建议您存储日期（作为类型为
LocalDate
的对象），并应用
date.plusWeeks（1）
或类似的方法。您始终可以查询星期日、基于年的星期、星期年、日历年等的日期，这比保存年的星期和日历年要好得多

测试后更新：

现在，我已经将年更改为周年，并且在设置日期时也更改了方法调用的顺序（首先是周年，然后是周，最后是星期几）。在这些更改之后，根据我自己的测试，您的代码将可以正常工作（尽管我仍然建议您简化类状态和逻辑）。这里是我的完整更改和更正代码：

import org.joda.time.LocalDate;

public class WonkyWeeks {
    int year;
    int week;

    public void backUpOneWeek() {
        LocalDate today =
            new LocalDate().withWeekyear(year).withWeekOfWeekyear(week).withDayOfWeek(4);
        LocalDate adayago = today.minusDays(1);
        System.out.println(adayago + " - removed one day");
        LocalDate twodaysago = adayago.minusDays(1);
        System.out.println(twodaysago + " - removed one day");
        LocalDate threedaysago = twodaysago.minusDays(1);
        System.out.println(threedaysago + " - removed one day");
        LocalDate fourdaysago = threedaysago.minusDays(1);
        System.out.println(fourdaysago + " - removed one day");
        LocalDate fivedaysago = fourdaysago.minusDays(1);
        System.out.println(fivedaysago + " - removed one day");
        LocalDate sixdaysago = fivedaysago.minusDays(1);
        System.out.println(sixdaysago + " - removed one day");
        LocalDate lastWeek = sixdaysago.minusDays(1);

        week = lastWeek.getWeekOfWeekyear();
        year = lastWeek.getWeekyear();
        System.out.println(lastWeek + " - Removed one full week");
    }

    public void forwardOneWeek() {
        LocalDate today =
            new LocalDate().withWeekyear(year).withWeekOfWeekyear(week).withDayOfWeek(4);
        LocalDate tomorrow = today.plusDays(1);
        System.out.println(tomorrow + " - added one day");
        LocalDate dayAfterTomorrow = tomorrow.plusDays(1);
        System.out.println(dayAfterTomorrow + " - added one day");
        LocalDate threeDaysFromNow = dayAfterTomorrow.plusDays(1);
        System.out.println(threeDaysFromNow + " - added one day");
        LocalDate fourDaysFromNow = threeDaysFromNow.plusDays(1);
        System.out.println(fourDaysFromNow + " - added one day");
        LocalDate fiveDaysFromNow = fourDaysFromNow.plusDays(1);
        System.out.println(fiveDaysFromNow + " - added one day");
        LocalDate sixDaysFromNow = fiveDaysFromNow.plusDays(1);
        System.out.println(sixDaysFromNow + " - added one day");
        LocalDate nextWeek = sixDaysFromNow.plusDays(1);

        week = nextWeek.getWeekOfWeekyear();
        year = nextWeek.getWeekyear();
        System.out.println(nextWeek + " - Added one week");
    }

    public void thisWeek() {
        LocalDate thisWeek =
            new LocalDate().withWeekyear(year).withWeekOfWeekyear(week).withDayOfWeek(4);
        System.out.println(thisWeek + " - This is the current week");
    }

    public static void main(String[] args) {
        WonkyWeeks wonky = new WonkyWeeks();
        wonky.week = 2;
        wonky.year = 2015;
        wonky.thisWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.backUpOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
        wonky.forwardOneWeek();
    }
}

更改代码的输出：

2015-01-08 - This is the current week
2015-01-07 - removed one day
2015-01-06 - removed one day
2015-01-05 - removed one day
2015-01-04 - removed one day
2015-01-03 - removed one day
2015-01-02 - removed one day
2015-01-01 - Removed one full week
2014-12-31 - removed one day
2014-12-30 - removed one day
2014-12-29 - removed one day
2014-12-28 - removed one day
2014-12-27 - removed one day
2014-12-26 - removed one day
2014-12-25 - Removed one full week
2014-12-24 - removed one day
2014-12-23 - removed one day
2014-12-22 - removed one day
2014-12-21 - removed one day
2014-12-20 - removed one day
2014-12-19 - removed one day
2014-12-18 - Removed one full week
2014-12-17 - removed one day
2014-12-16 - removed one day
2014-12-15 - removed one day
2014-12-14 - removed one day
2014-12-13 - removed one day
2014-12-12 - removed one day
2014-12-11 - Removed one full week
2014-12-12 - added one day
2014-12-13 - added one day
2014-12-14 - added one day
2014-12-15 - added one day
2014-12-16 - added one day
2014-12-17 - added one day
2014-12-18 - Added one week
2014-12-19 - added one day
2014-12-20 - added one day
2014-12-21 - added one day
2014-12-22 - added one day
2014-12-23 - added one day
2014-12-24 - added one day
2014-12-25 - Added one week
2014-12-26 - added one day
2014-12-27 - added one day
2014-12-28 - added one day
2014-12-29 - added one day
2014-12-30 - added one day
2014-12-31 - added one day
2015-01-01 - Added one week
2015-01-02 - added one day
2015-01-03 - added one day
2015-01-04 - added one day
2015-01-05 - added one day
2015-01-06 - added one day
2015-01-07 - added one day
2015-01-08 - Added one week

我建议将您的示例代码缩减到复制此行为所需的基本内容。（当你这样做的时候，你可能会发现你自己的逻辑中有一个bug）@b战神它怎么可能被进一步分解呢？代码所做的一切就是创建一个
LocalDate
的实例，将其设置为一年中的第二个星期四，然后使用Joda提供的
plus
和
plus
方法进行前滚和后滚？或者更确切地说，它创建了相当多的实例，但我认为所有这些都是一样的？就我目前为止的推理而言，问题必须是Joda，与12-24和01-01的具体日期有关。我使用相同的方法（
backUpOneWeek（）
和
forwardOneWeek（）
）向前和向后滚动每个“周”。如果问题出在我的程序逻辑上，那么错误不应该在每个方法调用中重现吗？您可以通过设置一个日期，然后按设定的数量向前滚动，而不是链接一堆“添加时间”和“删除时间”调用来重现行为吗？您所看到的行为可能是由于添加了“天”的间隔而导致的，但toString方法不考虑闰秒。（有些日子实际上比24*60*60秒长）解释得很好。我试图收集我的答案中的所有信息，但找不到比你更好的+哇，解释得真不错！非常感谢！向上投票并正确回答！=）