8291954: Use Optional.isEmpty instead of !Optional.isPresent in java.base

[turbanoff]

I propose to replace usages of !Optional.isPresent() with Optional.isEmpty method.
It's makes code a bit easier to read.
Noticing negation before long chain of method calls is hard.

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Progress

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Issue

• JDK-8291954: Use Optional.isEmpty instead of !Optional.isPresent in java.base

Reviewers

• Jaikiran Pai (@jaikiran - Reviewer)
• Alan Bateman (@AlanBateman - Reviewer)
• Lance Andersen (@LanceAndersen - Reviewer)
• Roger Riggs (@RogerRiggs - Reviewer)
• Brian Burkhalter (@bplb - Reviewer)

Reviewing

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Update a local copy of the PR:
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$ git pull https://git.openjdk.org/jdk pull/9697/head

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$ git pr checkout 9697

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[openjdk]

@turbanoff The following label will be automatically applied to this pull request:

• core-libs

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[mlbridge]

Webrevs

• 00: Full (12b447e7)

[jaikiran]

The changes look fine to me.

[openjdk]

@turbanoff This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8291954: Use Optional.isEmpty instead of !Optional.isPresent in java.base

Reviewed-by: jpai, alanb, lancea, rriggs, bpb

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 70 new commits pushed to the master branch:

• b17a745: 8291637: HttpClient default keep alive timeout not followed if server sends invalid value
• 0da4314: 8288732: Reduce runtime of java.util.concurrent microbenchmarks
• 88c96dd: 8291947: riscv: fail to build after JDK-8290840
• dd7f2d9: 8290090: Change CodeBlobType from unscoped enum to enum class
• 4c652d9: 8291952: riscv: Remove PRAGMA_NONNULL_IGNORED
• b0d6952: 8291823: IGV: Fix "Save selected groups"
• 504a626: 8291799: IGV: make "Selection mode" a toggle button
• 6e7cd76: 8291061: Improve thread safety of FileTime.toString and toInstant
• 477f471: Merge
• 4b3dfe1: 8283276: java/io/ObjectStreamClass/ObjectStreamClassCaching.java fails with various GCs
• ... and 60 more: https://git.openjdk.org/jdk/compare/32d410a1af65f12f5b27f3685e1e803d876816e8...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[AlanBateman]

Looks good. The isEmpty was added in Java 11 so I think most (if not all) of these pre-date this method.

[turbanoff]

/integrate

[openjdk]

Going to push as commit ae52053.
Since your change was applied there have been 76 commits pushed to the master branch:

• 87cda21: Merge
• 5963300: 8290562: ThreadMXBean.getThread{Cpu,User}Time fails with -XX:-VMContinuations
• 0657acf: 8289249: Add methods to Elements for record constructors
• b66a0d1: 8291992: [REDO2] ProblemList multiple tests in -Xcomp mode due to JDK-8291649
• 9bff3b7: 8291990: [REDO] ProblemList multiple tests in -Xcomp mode due to JDK-8291649
• f9bb367: 8291653: G1 refinement incorrectly expects always-valid HeapRegion out of the Hot Card Cache
• b17a745: 8291637: HttpClient default keep alive timeout not followed if server sends invalid value
• 0da4314: 8288732: Reduce runtime of java.util.concurrent microbenchmarks
• 88c96dd: 8291947: riscv: fail to build after JDK-8290840
• dd7f2d9: 8290090: Change CodeBlobType from unscoped enum to enum class
• ... and 66 more: https://git.openjdk.org/jdk/compare/32d410a1af65f12f5b27f3685e1e803d876816e8...master

Your commit was automatically rebased without conflicts.

[openjdk]

@turbanoff Pushed as commit ae52053.

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