[Feat]: Move to latest Java LTS to compile, target oldest LTS

[jmesnil]

Is your feature request related to a problem? Please describe.

I wonder if this project would benefit by compiling with the latest Java LTS (25)
and target the oldest supported LTS (17).

After looking at some reviews, we would benefit from being able to use language features that appears after 17.

Describe the solution you'd like

Move to Java 25 to compile the code.
Keep 17 as the target and release.

Describe alternatives you've considered

No response

Additional context

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[ehsavoie]

I'm not sure this is actually doable as it seems to fail as soon as you use 25 features in the code :(

[kabir]

We can still compile with 25, but need to avoid 25 features. I think in addition to the target setting there is also a source setting. The names might be different, but we should set both to 17.

EDIT: I see Jeff mentions using 25 features, and I think that isn't possible as Emmanuel points out. But there were some other reasons on a call we were on recently, which I can't remember. I'm trying to find out

[kabir]

I found the person. It seems the idea is that you can have a multi-release jar to support older versions. So you can use Java 25 features where they provide benefit, and support older version with alternative classes. But that implies that classes exposed to users should remain on 17, and probably also the main integration points on the server side.

Another driver, is apparently that some (Maven?) plugins are now minimum Java 17, and there are compiler bug fixes in later releases.

[ehsavoie]

@kabir multi-release jars wasn't the goal, We wanted to use Java language new features, but having 2 classes to support defeats that goal I think