Are you sure?
I'm asking about the limitations of Ruby on Rails (not JRuby on Rails)
integrating with Java.
I found 'Ruby Java Bridge', so that Ruby can use Java libraries.
I have been asked to investigate the possibility of using RoR, on top
of an existing java infrastructure. (but specifically not JRuby)
Have you looked for a forum for the Ruby Java Bridge? Ruby on Rails has
nothing to do with Java so this question is still off-topic for this
particular forum IMHO.
If there is no specific forum for the Ruby Java Bridge, then this
question still belongs on the general Ruby forum since that technology
has no relation to the Rails framework.
Although I know you're not looking for JRuby on Rails specifically, you
still might get better responses from the JRuby forum. At least those
watchers are somewhat interested in running Ruby on the Java VM.
I'm simply trying to direct your question to the proper forum, and I
don't believe this is it.