8207329: Add NIL Constant to UUID

[Fleshgrinder]

Adds a constant for the special NIL UUID where all bits are zero to java.util.UUID. The 8207329 mentions the usage of it to avoid null, it for sure is also very handy in testing where a UUID is required and we do not care about its actual value. Using a random UUID stresses the PRNG for no good reason.

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Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Integration blockers

 ⚠️ The change requires a CSR request to be approved.
 ⚠️ Title mismatch between PR and JBS for issue JDK-8207329

Issue

• JDK-8207329: Add a constant for a nil UUID value of all zeros: java.util.UUID.NIL ⚠️ Title mismatch between PR and JBS. ⚠️ Issue is not open.

Download

$ git fetch https://git.openjdk.java.net/jdk pull/1460/head:pull/1460
$ git checkout pull/1460

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (5b61adb)

[Fleshgrinder]

/csr

[openjdk]

@Fleshgrinder has indicated that a compatibility and specification (CSR) request is needed for this pull request.
@Fleshgrinder please create a CSR request and add link to it in JDK-8207329. This pull request cannot be integrated until the CSR request is approved.

[RogerRiggs]

The bug report does not make a strong case for adding a NIL constant to the UUID API.
It would add (a small amount) to both footprint and startup time with very limited benefit.
Any application needing a placeholder can do so itself and all existing applications take care of their own needs.

[Fleshgrinder]

For me it's mostly useful in tests but we cannot ship test only code. We could fix the issues you mention through lazy initialization, or we simply close the PR and ticket and state that the construction via new UUID(0, 0) is already simple enough.

[RogerRiggs]

There being no other comments supporting this enhancement, I propose to close this PR without integrating.
I'll take care of closing the bug as will-not-fix. It can be reopened if new information becomes available.

For any API addition, its useful to do an email query on core-libs-dev@openjdk.net to see if there is support for API enhancements. Thank you.