Proposal: Bump minimum JDK version for JavaFX 23 to JDK 21

[John Hendrikx]

+1

On 16/02/2024 23:11, Kevin Rushforth wrote:
> All,
>
> Even though we build JavaFX binaries with JDK 21 as the boot JDK, the 
> latest version of JavaFX still runs with JDK 17, although it isn't 
> tested with older JDK versions. In order for JavaFX to be able to use 
> newer JDK features, such as code snippets (in API docs), record 
> patterns, pattern matching for switch statements, and so forth, we 
> need to increase the minimum version of the JDK that can run the 
> latest JavaFX. Additionally, there is an ongoing cost to keeping 
> JavaFX buildable and runnable on older versions of Java, and very 
> little reason to continue to do so.
>
> A question was raised [1] as to whether we should go even further and, 
> once JDK 22 is released, jump straight to JDK 22 as a minimum. While 
> we could do that, I feel that there isn't sufficient justification for 
> this at this time, although we could reconsider for next release.
>
> To this end, I propose to bump the minimum version of the JDK needed 
> to run JavaFX 23 to JDK 21. I filed JDK-8321603 [2] to track this and 
> prepared PR  #1370 [3] (I've moved the PR back to Draft, pending this 
> discussion). This will not affect update releases of earlier versions 
> of JavaFX (e.g., JavaFX 21.0.NN or JavaFX 17.0.NN), which will 
> continue to run with the same minimum JDK that they run on today.
>
> As a reminder, we only assure that JavaFX NN will run with JDK NN-1 or 
> later, although in practice, we don't bump the minimum required JDK 
> version without a good reason. For example, while JavaFX 22 is built 
> using JDK 21 as the boot JDK, it produces class files that will run 
> with JDK 17, using "--release 17". The proposed change discussed here 
> would update that in JavaFX 23 to "--release 21".
>
> NOTE: this will not be an invitation to do wholesale refactoring of 
> existing classes or methods to use newer language features (e.g., a PR 
> that refactors existing switch statements and switch expressions into 
> pattern-matching switch expressions would not be welcome). Rather, 
> this can be seen as enabling judicious use of new features in new 
> code, much as we did when we started allowing the use of "var", 
> records, and pattern-matching instanceof.
>
> Comments are welcome.
>
> -- Kevin
>
> [1] 
> https://mail.openjdk.org/pipermail/openjfx-dev/2023-December/044081.html
> [2] https://bugs.openjdk.org/browse/JDK-8321603
> [3] https://github.com/openjdk/jfx/pull/1370
>