那些遇到过的问题

Joda Time minusweeks()和plusweeks()一年中断2014/2015细分？

Jer*_*emi 10 java jodatime

我可能在这里遗漏了一些东西,但我似乎无法在Joda Time的文档中找到解释或在任何地方找到解释.看起来Joda Time在计算几周时加入和减去从一年到下一年的周数时都会崩溃.

谁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

我从下面的代码中得到以下输出:

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.
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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();
    }
}
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经过进一步测试,它变得更加混乱.我试过添加和删除几天而不是几周,由于某种原因它似乎跳过日期.

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
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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 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();
    }
}
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Men*_*ild 2

Joda-Time 是正确的，但不是你的逻辑。您必须仔细区分“日历年”（从 1 月 1 日开始）和周日期年份（如 ISO-8601 中定义，也称为“基于周的年份”或简称为“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();
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这些行的问题在于，周与基于周的年份相关，而不是第二行所示的日历年。请记住，基于周的年份可能比日历年（1 月 1 日）少一年。例如，[2014-12-31] 与 [2015-W01-3] 是同一日期。另请记住，Joda-Time 提供了另一种称为 的方法getWeekyear()。

然后您将使用这两个值来以这种方式操作日期：

LocalDate today = new LocalDate()
        .withDayOfWeek(4)
        .withWeekOfWeekyear(week)
        .withYear(year);
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又是同样的术语问题。当试图保留当前周年2015 中的星期几时，该方法withWeekOfWeekyear(week)已经可以更改日历年并将每月的某一天移至另一天，而不是 2014 日历年产生意外的日期偏移！整个代码产生的结果并不是真正可预测的，并且会让每个人感到惊讶。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？！）。下面的代码看起来更健康：

LocalDate today = new LocalDate()
        .withWeekyear(year)
        .withWeekOfWeekyear(week)
        .withDayOfWeek(4);
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解决方案：您应该更好地在代码中引用周年，而不是日历年。或者甚至更好：如果您只想添加或删除周，那么我建议您存储日期（作为类型的对象LocalDate）并应用date.plusWeeks(1)或类似。您始终可以查询星期几、基于年份的星期几、年份、日历年等的日期。比保存一年中的星期和日历年要好得多。

测试后更新：

我现在已将年份更改为周年，并且在设置日期时更改了方法调用的顺序（首先是周年，然后是周，最后是周中的日）。经过这些更改后，根据我自己的测试，您的代码将正常工作（尽管我仍然建议您简化类状态和逻辑）。这是我完整更改和更正的代码：

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();
    }
}
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更改后的代码的输出：

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
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