It sits on top of our own IP database which is 6 figures in lines and is written in C++. Java has fancy bells and whistles when it comes to IDE's, but that's all they are.
I just think it's foolish to think Java is the only language that can handle large codebases. I mean just look at the linux kernel.
EDIT: Removed comment about processing capabilities because it's irrelevant to the discussion. I left my original comments about lines and the IDE though.