I’d say Java has better tool support (debuggers, IDEs, refactoring, etc.) than Perl.
It also needs them far more badly than Perl. Not only is Java generally more verbose, but it is deliberately designed to prevent you from abstracting your code past a point. As a result, large Java systems grow quadratically with the number of interacting parts in the system – and without tools, well, you aren’t exactly lost, but it’s going to be really unfun.
(I was going to say that the only thing Perl is still missing is a really good graphical debugger for people who prefer working with them (I prefer logging, but I acknowledge that it’s not the same for everyone), but then I remembered Devel::ebug, and now I’m not entirely sure.)
So to the OP, I would suggest reimplementing some small but significant portion of the system in both Perl and Java, and see how large they grow. It is a demonstrated fact that bug counts are invariably linear with the size of the codebase, even though noone has a deep understanding of why; it is also common experience that maintenance effort grows faster than linearly with the bug count. Java solutions almost always cost more and take longer than ones written in a more expressive language. I’m not even advocating Perl in specific here – pick Python if you want to, just stay away from the Java albatross.
Makeshifts last the longest.