<i18n dev> RFR: 8285844: TimeZone.getTimeZone(ZoneOffset) does not work for all ZoneOffsets and returns GMT unexpected [v2]

[Naoto Sato]

On Mon, 9 May 2022 22:29:50 GMT, Uwe Schindler <uschindler at openjdk.org> wrote:

>> Naoto Sato has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fixed offsets in milliseconds, added test variations, refined Custom ID definitions
>
> src/java.base/share/classes/java/util/TimeZone.java line 539:
> 
>> 537:     public static TimeZone getTimeZone(ZoneId zoneId) {
>> 538:         String tzid = zoneId.getId(); // throws an NPE if null
>> 539:         if (zoneId instanceof ZoneOffset zo) {
> 
> I like this because it is much faster than the conversion to ZoneId and parsing it back! It is similar to use of SimpleTimeZone, but this is better as the returned timezone is unmodifiable, correct?

Yes, and it aligns with the other call site (line 588).

> test/jdk/java/util/TimeZone/ZoneOffsetRoundTripTest.java line 43:
> 
>> 41:     private Object[][] testZoneOffsets() {
>> 42:         return new Object[][] {
>> 43:                 {ZoneId.of("Z"), 0},
> 
> I know, `ZoneId.of()` should parse this as a `ZoneOffset` and return a `ZoneOffset` instance, but maybe add also the other string variants with prefix (`ZoneId.of("UTC+00:00:01")` or `ZoneId.of("GMT+00:00:01")` as data items. Maybe also use `ZoneOffset.of()` for the plain zones to be explicit.

Added them except "UTC+...", as it is not recognizable as a Custom ID.

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PR: https://git.openjdk.java.net/jdk/pull/8606