I have done some of that game with Test::Unit, porting the JUnit framework (Kent Beck and Erich Gamma) to Perl. You can get a good headstart by text-filtering method declarations over into Perl, but after that, you need to get manual.

A warning: methods dispatching on the type of some basic type argument (e.g., string vs. integer) can be a little problematic.

Also, you will find that just porting the methods of the classes will lead to very artifical Perl.

FYI, I wrote Test::Unit::InnerClass to make porting Java to Perl easier. This class emulates the anonymous inner classes syntax feature of Java in Perl. It may help you in your adventures.

Good Luck!

Christian Lemburg
Brainbench MVP for Perl
http://www.brainbench.com