Java 1.8时间功能 [英] Java 1.8 time functionality
问题描述
因此，Java 1.8附带了一大堆新的（和旧的）类来管理时间计算： java.time.Instant ， java。 time.LocalTime ， java.time.temporal.ChronoUnit ，也许更多......
So Java 1.8 comes with a whole new (and old) bunch of classes to manage time calculations: java.time.Instant, java.time.LocalTime, java.time.temporal.ChronoUnit, and maybe more...
但为什么没有简单的方法来计算其中任何一个之间的时差？我希望time_later - time_earlier是最常用的时间操纵，但这是无处可见的。我无法从另一个中减去一个LocalTime并获得一个新的LocalTime;我不能从另一个中减去一个瞬间来获得一个新的瞬发。相反，我必须摆弄ChronoUnits.between，以及长毫秒和其他什么来实现这个非常有用的东西。
But why is there no simple way to calculate the time difference between any of these? I would expect "time_later - time_earlier" to be the most used manipulation of time, but this is nowhere to be seen. I cannot subtract one LocalTime from the other and get a new LocalTime; I cannot subtract one Instant from the other to get a new Instant. Instead I have to fiddle with ChronoUnits.between, and long milliseconds and whatnots to achieve this very useful thing.
为什么会这样？必须要发生一些我没有得到的事情？或者我只是愚蠢......？
Why is this? There has to be something going on that I do not get? Or I'm just daft...?
推荐答案
在Java 8之前，你问题的通常答案是使用Joda Time
Before Java 8, the usual answer to your question was "use Joda Time"
- http://joda-time.sourceforge.net/faq.html
但Joda Time（Stephen）的作者Colebourne）深入参与了新的Java 8时间类和方法。以下是两篇非常好的文章：
But the author of Joda Time (Stephen Colebourne) was deeply involved in the new Java 8 time classes and methods. Here are two very good articles:
- http://www.oracle.com/technetwork/articles/java/jf14-date-time-2125367.html
对于您的具体问题，您可能需要考虑Java 8持续时间和LocalTime，LocalDate和/或LocalTimeDate（以及其他）选项）：
For your specific question, you might want to consider Java 8 "Duration" and "LocalTime", "LocalDate" and/or "LocalTimeDate" (among other options):
// A duration of 3 seconds and 5 nanoseconds
Duration duration = Duration.ofSeconds(3, 5);
Duration oneDay = Duration.between(today, yesterday);
// Tomorrow
LocalDate tomorrow = LocalDate.now().plusDays(1);
// Yesterday
LocalDate yesterday = LocalDate.now().plusDays(-1);
// before 5 houres and 30 minutes
LocalDateTime dateTime = LocalDateTime.now().minusHours(5).minusMinutes(30);
这篇关于Java 1.8时间功能的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
