我可能会在这里遗漏一些东西,但是我似乎无法在Joda Time的文档中找到解释,或者真的在任何地方找不到解释.当你从一年到另一年的时间里加上和减去周数时,犹他时间似乎算下来了几周.
任何人都可以解释为什么会发生这种情况,以及如何正确地做到这一点？
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();
}
}
经过进一步的测试,它变得更加混乱.我尝试添加和删除日子,而不是几周,由于某种原因似乎跳过日期.
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
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();
}
}
解决方法
Joda-Time是正确的,但不是你的逻辑.你必须仔细地在“日历年”(从1月1日开始)到周末的年份(如ISO-8601中定义的,也称为“周年”或简称“周” -年”).
例如,您在类中使用两个不相互关联的成员来存储中间结果：
week = nextWeek.getWeekOfWeekyear(); year = nextWeek.getYear();
这些方面的问题是,这周与周年相关,而不是第二行表示的日历年.请记住,周一年可能比1月份的历年减少一年.例如[2014-12-31]与[2015-W01-3]相同的日期.还要记住,Joda-Time提供另一种称为getWeekyear()的方法.
那么你将使用这两个值来操作这个日期：
LocalDate today = new LocalDate()
.withDayOfWeek(4)
.withWeekOfWeekyear(week)
.withYear(year);
同样的术语问题.而周末(WweekOfWeekyear(周))的方法已经可以改变日历年,并将月日转移到另一天,当时要在2015年的当前周内保留星期几,而不是2014年的日历日期班！整个代码产生的结果不是真正可预测的,并且会让每个人都惊喜.另一个大问题是方法调用的顺序是重要的,因为周操纵是指当前的周年(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：您应该更好地参考您的代码中的周年,而不是日历年.或者甚至更好：如果你只是想添加或删除几周,那么我建议你存储日期(作为对象的类型LocalDate)而不是应用date.plusWeeks(1)或类似的.您可以随时查询星期几,星期,日历年等的日期.比保存年度和日历年要好得多.
测试后更新：
我现在已将年份改为周年,并在设置日期时更改方法通话的顺序(首先是周年,然后是周,最后是星期几).这些更改后,您的代码将根据我自己的测试工作正常(尽管我仍然建议您简化您的类状态和逻辑).这里我的全部更改和更正的代码：
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();
}
}
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
