如何规范ZonedDateTime以便.equals()工作?

显然，当区域名称不同时，使区域相等是不够的.通过使用ZoneOffset.UTC构造第一个ZonedDateTime，两者将具有相同的时区，因此将相等.进行更改后，至少在Mac上，zdt1.getZone() == zdt2.getZone()现在评估为true.作为对问题的更直接答案，您可以按以下方式规范化ZonedDateTime对象(带有分号的Java语法，请自行翻译): zdt1 = zdt1.withZoneSameInstant(zdt1.getZone().normalized());当然，与zdt2类似. ZoneId.normalized()承诺在可能的情况下返回ZoneOffset，这取决于您的情况.因此，在您的情况下，它确实使两个对象在equals()下相等.在所有其他情况下，我都不确定.一种比较安全的方法是让比较显式地处理不同但相等的时区:zdt1.toInstant().equals(zdt2.toInstant()) && zdt1.getZone().getRules().equals(zdt2.getZone().getRules())这将使用您问题中的两个日期时间计算为true. BTW isEqual() 仅比较时间点，而不比较所有区域，这就是为什么它不关心的原因.I have code, similar to this:import java.time._object app { def main (args :Array[String]) = { println("app started") // create two ZonedDateTime objects for 1st Jan 2018, 10am UTC // using separate methods val zdt1 = ZonedDateTime.of(2018, 1, 1, 10, 0, 0, 0, ZoneId.of("UTC")) val zdt2 = ZonedDateTime.parse("2018-01-01T10:00:00Z") println(s"COMPARING: $zdt1 and $zdt2") println("== check: " + (zdt1 == zdt2)) println(".equals check: " + (zdt1.equals(zdt2))) println(".isEqual check " + (zdt1.isEqual(zdt2))) println("app finished") }}Code available here: https://ideone.com/43zf8BThe issue:these ARE both typed ZonedDateTime objectsthey are equivalent according to the .isEqual() method..they are not equivalent according to .equals() methodHowever my test suite uses deep matching using beEqualsoperations against the classes these datetime instances arein, therefore I need a way to normalise them so that.equals() returns true.how can I normalise them please? 解决方案 If I create zdt1 with ZonedDateTime.of(2018, 1, 1, 10, 0, 0, 0, ZoneOffset.UTC), the two objects are equal under equals() (still not under == in Java).Apparently it’s not enough for the zones to be equivalent when their names are different. By using ZoneOffset.UTC for constructing the first ZonedDateTime, both will have the same time zone and will thus be equal. With my change, at least on my Mac, zdt1.getZone() == zdt2.getZone() now evaluates to true.As a more direct answer to your question, you may normalize your ZonedDateTime objects this way (Java syntax with semicolon, please translate yourself): zdt1 = zdt1.withZoneSameInstant(zdt1.getZone().normalized());Similarly for zdt2, of course. ZoneId.normalized() promises to return a ZoneOffset where possible, which it is in your case. So in your case it does make two objects that are equal under equals(). I’m not sure it will in all other cases.A safer way would be to have the comparison explicitly take care of different but equal time zones:zdt1.toInstant().equals(zdt2.toInstant()) && zdt1.getZone().getRules().equals(zdt2.getZone().getRules())This evaluates to true with your two date-times from the question.BTW isEqual() compares the instants in time only, not the zones at all, which is why it didn’t care. 这篇关于如何规范ZonedDateTime以便.equals()工作?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！ 上岸，阿里云！