8256014: Eliminate the warning about serialization in non-public API of Swing

[mrserb]

As part of the serialization cleanup, I would like to remove the serialization warning below from the non-public API(mostly motif and windows L&Fs). Later I will remove it from the public API and move this warning to the "javax.swing" package spec.

 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is appropriate
 * for short term storage or RMI between applications running the same
 * version of Swing. A future release of Swing will provide support for
 * long term persistence.

Note that this warning is useless because the UI delegates(parts of L&F) should never be serialized. Such classes were marked as "Serializable" by accident. If the component like JButton is serialized then parts related to the L&F are removed from the stream. This is because default L&F could be different before/after serialization.

---

Progress

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

Testing

	Linux x64	Linux x86	Windows x64	macOS x64
Build	✔️ (5/5 passed)	✔️ (2/2 passed)	✔️ (2/2 passed)	✔️ (2/2 passed)
Test (tier1)	✔️ (9/9 passed)	✔️ (9/9 passed)	✔️ (9/9 passed)	✔️ (9/9 passed)

Issue

• JDK-8256014: Eliminate the warning about serialization in non-public API of Swing

Reviewers

• Phil Race (@prrace - Reviewer)
• Prasanta Sadhukhan (@prsadhuk - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jdk pull/1110/head:pull/1110
$ git checkout pull/1110

[bridgekeeper]

👋 Welcome back serb! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

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

• swing

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 00: Full (94150bd)

[openjdk]

@mrserb 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:

8256014: Eliminate the warning about serialization in non-public API of Swing

Reviewed-by: prr, psadhukhan

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 7 new commits pushed to the master branch:

• 3ce09c0: 8255920: J2DBench should support CS_PYCC color profile
• 2c8f4e2: 8255799: AArch64: CPU_A53MAC feature may be set incorrectly
• 2cad836: 8255575: java.awt.color.ICC_ColorSpace is not thread-safe
• a53b12d: 8255722: Create a new test for rotated blit
• f39a2c8: 8256015: Shenandoah: Add missing Shenandoah implementation in WB_isObjectInOldGen
• ed7526a: 8247872: Upgrade HarfBuzz to the latest 2.7.2
• 6a183fb: 8255562: delete UseRDPCForConstantTableBase

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

[mrserb]

/integrate

[openjdk]

@mrserb Since your change was applied there have been 8 commits pushed to the master branch:

• 2d6c28d: 6847157: java.lang.NullPointerException: HDC for component at sun.java2d.loops.Blit.Blit
• 3ce09c0: 8255920: J2DBench should support CS_PYCC color profile
• 2c8f4e2: 8255799: AArch64: CPU_A53MAC feature may be set incorrectly
• 2cad836: 8255575: java.awt.color.ICC_ColorSpace is not thread-safe
• a53b12d: 8255722: Create a new test for rotated blit
• f39a2c8: 8256015: Shenandoah: Add missing Shenandoah implementation in WB_isObjectInOldGen
• ed7526a: 8247872: Upgrade HarfBuzz to the latest 2.7.2
• 6a183fb: 8255562: delete UseRDPCForConstantTableBase

Your commit was automatically rebased without conflicts.

Pushed as commit c7551c3.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.