And if your only consideration is the size of the library, don't bother with perl. Java's library collection dwarfs it easily.
I've seen (and track) CPAN's numbers. Where can I see similar statistics for Java's library collection?
No, I'm not aware of a central CPAN-like repo for Java, so what?
If what you say is true, you should easily be able to provide hard numbers.
There is a long tail for libraries, too. That is, the sum of all seldomly needed libraries is big. So you will often find yourself in need of libs where you'll get a better hit rate on CPAN.