8345343: Restore the preview status of java.lang.classfile.components package

[liach]

The java.lang.classfile.components package was underused and had almost no usage feedback; as a result, it did not caught attention during the preview process of the Class-File API, until the late adoption when Class-File API is sure to become finalized. In the previous rounds of reviews by other engineers, most of the review efforts were devoted to other core modeling and API classes, and components was largely omitted; a few questions were asked, but no solution were proposed and the questions were forgotten.

To compensate in such a short time to the stabilization of JDK 24, we propose to restore the preview status of the java.lang.classfile.component package and its member classes. This allows us to better consider the role of this package and its members.

See https://mail.openjdk.org/pipermail/classfile-api-dev/2024-November/000611.html for initial problem discovery and https://mail.openjdk.org/pipermail/classfile-api-dev/2024-December/000613.html for revision proposal.

See the CSR for alternative solutions and why they were not chosen.

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change requires CSR request JDK-8345344 to be approved

Issues

• JDK-8345343: Restore the preview status of java.lang.classfile.components package (Bug - P3)
• JDK-8345344: Restore the preview status of java.lang.classfile.components package (CSR)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/22501/head:pull/22501
$ git checkout pull/22501

Update a local copy of the PR:
$ git checkout pull/22501
$ git pull https://git.openjdk.org/jdk.git pull/22501/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 22501

View PR using the GUI difftool:
$ git pr show -t 22501

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/22501.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back liach! 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]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

@liach The following labels will be automatically applied to this pull request:

• compiler
• core-libs

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

[mlbridge]

Webrevs

• 00: Full (51252339)

[liach]

Closing; after studying, it is now too late to mark this package preview or incubating, as the JEP does not provide for such. Withdrawing this to internal is the only option aside from letting this through.