I agree that you only want one constants file. Since Java is compiled, you can add a compiler step to generate the java constants file off of your Perl one. You could even write the code to do that in Perl.

Alternatively, you can write your constants in Java and write a constants module in Perl which uses AUTOLOAD to cull them from the java file as needed. This is a particularly cool way to do it (in my opinion) and it is a great use for AUTOLOAD. I actually did something similar for a company, where I had a hash table of constants and an AUTOLOADer to convert them to subroutines as needed. But watch out for non-scalar constants... arrays and hashes don't play as nice with eval.

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