Comment by nicoburns

You can call into to the JVM via FFI (e.g. using the jni crate in Rust), but it's not very nice. And most of the abstractions people have written thus far seem to be primarily (or solely) targeting the "Java calls into native code" use case rather than the "native code calls into Java" use case.

I'd love to see something better here. I suspect it's possible.