RFR: 8334015: Add Support for UUID Version 7 (UUIDv7) defined in RFC 9562 [v12]

[Roger Riggs]

On Thu, 3 Jul 2025 09:53:30 GMT, Kieran Farrell <kfarrell at openjdk.org> wrote:

>> src/java.base/share/classes/java/util/UUID.java line 212:
>> 
>>> 210:      * @since 26
>>> 211:      */
>>> 212:     public static UUID unixEpochTimeMillis() {
>> 
>> Is there a list anywhere on the names that have been discussed already? Asking because the existing static factory method for a type 4 is randomUUID().  Also, there are several methods (esp. in java.time) that use "Epoch" in method names name rather than "Unix Epoch". Also if you rename the timestamp parameter to something that includes "millis" in the name then it would help usage in IDEs where it's more obvious at the use-site that the parameter is in millis.
>
> The original proposed name was `timestampUUID` but it was decided against to avoid confusion with UUID-v1, which is also time-based, there hasnt been much discussion beyond that. Maybe something like `epochMilliUUID()` would better follow the naming conventions?
> 
> Reagarding the parameter, updating to something like `epochMillis` or `timestampMillis` would make sense.

The `UUID.epochMillis()` and `UUID.epochMillis(long timestamp)`  is concise and identifies both the Unix Epoch and the granularity of millis.
(Sorry for the long absence from this thread).

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PR Review Comment: https://git.openjdk.org/jdk/pull/25303#discussion_r2323539314