proposal for preferred jdk in ports

Hi,

I want to get some feedback on a proposal in a change on which JDK is preferred in ports.

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=293756
The idea came from talks in other PRs with ideas about picking a preferred JDK.

My proposal is attachment: https://bugs.freebsd.org/bugzilla/attachment.cgi?id=268746&action=diff <https://bugs.freebsd.org/bugzilla/attachment.cgi?id=268746&action=diff>.

The idea explained. I hope I can explain it good enough.

TL;DR: prefer latest LTS JDK instead of oldest JDK from the support range.

Current situation:
1. If no JAVA_VERSION is defined, ports picks JAVA_DEFAULT (currently 21); this is a simple case and is fine as it is.
2. If JAVA_VERSION is a range like JAVA_VERSION=8 11 17 or JAVA_VERSION=17+, ports currently picks the lowest number. So here it pick 8 and 17 respectively.

New situation:
1. no JAVA_VERSION defined, still JAVA_DEFAULT is used; no changes, this is fine.
2. if JAVA_VERSION is a range we will now pick the highest LTS version. In the example above we will now pick 17 (for 8 11 17) and 25 (for 17+).

I think this better matches using modern software.

Some notes:
- I tested that in the current state of the ports tree all java ports still compile fine.
- The USES=java mechanism of looking for installed JDKs still works the same. If you only install jdk22 and no LTS versions it will pick the jdk22.

In the PR might be a little more elaborate explanation.

I hope people find this proposal; simple enough to adopt without to much risky changes.


Regards,

Ronald.