I’d like to be able to run Processing code in a java IDE (Netbeans) to see how it’d be possible to use Java Libraries with a processing sketch (or to use Java ways to run Java code in a browser).
I know there are posts on this subject on the Forum but I wonder if they are accurate with the lasts Processing versions.
Can you link to some of the resources you are looking at, then I can tell you if they are still correct or need updating.
As far as I know not a lot has changed and you can still use the core.jar that is bundled with Processing. It might have moved location within the bundle but it is still there and functions the same.
I made this template a while ago that will allow you to use Processing w kotlin and gradle, but Java is also supported.