Sorry, I think the first part of the problem was my misunderstanding of the final keyword in Java. I didn't realize that it was a declaration keyword. As such, something like Readonly is a perfect equivalent in Perl (although the additional recommendations are much appreciated).
As for the second issue, this doesn't have anything to do directly with refactoring. I simply pointed out that Fowler suggested this method for a sanity check before performing the refactor. I just thought this was useful enough to call out, much as I have mentioned testing techniques in other write-ups that don't directly relate to refactoring.
perl -e 'split//,q{john hurl, pest caretaker}and(map{print @_[$_]}(joi
+n(q{},map{sprintf(qq{%010u},$_)}(2**2*307*4993,5*101*641*5261,7*59*79
+*36997,13*17*71*45131,3**2*67*89*167*181))=~/\d{2}/g));'