Allow setting JDK to use

[rnett]

I have multiple JDKs installed, and I would like to be able to control which one my notebook runs with. Ideally this would be a per-notebook setting, but a per-jupyter instance setting would also work. JAVA_HOME does not seem to be used, so even just using that would be a significant upgrade.

If it's as simple as it looks (using JAVA_HOME here) I can make a PR.

[ileasile]

Yes, you can grab JAVA_HOME in the python code you've mentioned and use it for running a kernel. PRs are welcome

[rnett]

Trying to import the gradle project gives me lots of Could not resolve org.jetbrains.kotlin:kotlin-scripting-dependencies:1.5.30-dev-1502. errors, is there a repository I should add? I found TeamCity configs in settings, but I still get resolution errors unless I set the kotlin version to 1.5.20. It's a 401 error, is there a public version I can use?