Well I seem to have been bored as I decided to have a go at porting the LJM/LJMException classes to Scala.
So far everything seems to work correctly (although I have certainly not tested it vigorously).
I have posted the code to github here.
I wasn't sure how to update the version etc. in the comments without making it look like I had written it all (it was largely an automated port) so I just added my details at the bottom. I hope this is OK. If not, please let me know what to change it to.
I hope this is useful to someone. Let me know if there are any issues.