Does Java have a lot of modules already written for you?
Would your boss even consider letting Perl into the maintenance environment?
Are your Java skills better that your Perl skills?

You could develop the Java version on company time and the Perl version on your time. If Perl is as much better for the job than Java is, (as some here seem to think) then you should have the Perl version up and running before the Java version is anywhere near done.