Java 21 language features

[holgerfriedrich]

• use getFirst and getLast methods
• replace new Locale by Locale.of
• replace Paths.get by Path.of
• use ThreadLocalRandom.current().nextDouble()
• add @ Serial annotations

[andrewfg]

use getFirst and getLast methods

And maybe also replace list.add(index, ..) with list.addFirst(..) and list.addLast(..) for those special cases index == 0 resp. index == list.size() - 1. Although probably the latter is quite rare in OH since any sane developer would have simply used list.add(..). => WDYT?

[holgerfriedrich]

use getFirst and getLast methods

And maybe also replace list.add(index, ..) with list.addFirst(..) and list.addLast(..) for those special cases index == 0 resp. index == list.size() - 1. Although probably the latter is quite rare in OH since any sane developer would have simply used list.add(..). => WDYT?

This should already be included. I have seen one occurrence in the code, add(0, ...) in PersistenceExtensions.java.

[andrewfg]

It looks very clean. In particular the List.getFirst() calls. => LGTM

I assume you are working on a similar clean up in addons? But probably wait until the current round of fixes backported into 4.3 will have been completed.

[holgerfriedrich]

@andrewfg I have not started work on the add-ons repo. Last time when I introduced the Java 17 features (mainly instanceof patterns), there were a lot of complaints by add-on authors, as they intend to build and release for the previous 4.x release. I had deliberately waited an additional release cycle (so core used Java17 features one release before). We need to discuss how we want to approach this.

[kaikreuzer]

lgtm, many thanks!

[kaikreuzer]

Wrt add-on repo: Yes, I assume there would be quite some push-back. We should probably wait until 5.0 is released, so that it is easy for maintainers to build 4.x versions of it. It will also help for backporting code to the 4.3.x branch.