java - 为什么 GMT 和 UTC 时区没有相同的规则

Question

为什么下面一行打印错误？我认为它应该打印为真。

TimeZone.getTimeZone("UTC+5:30").hasSameRules(TimeZone.getTimeZone("GMT+5:30")

Answer 1

答案在 JavaDoc of TimeZone#getTimeZone 中:

the ID for a TimeZone, either an abbreviation such as "PST", a full name such as "America/Los_Angeles", or a custom ID such as "GMT-8:00"

Returns: the specified TimeZone, or the GMT zone if the given ID cannot be understood.

并且(来自 class documentation )

[...] The syntax of a custom time zone ID is:

  CustomID:
     GMT Sign Hours : Minutes
     GMT Sign Hours Minutes
     GMT Sign Hours

ID "UTC+5:30" 不是有效的时区 ID(根据方法/类的规范)，被解释为“GMT”时区，这与“GMT+5:30”区域。