I think the best advise is Don't try to write Perl code in Java, and also applies to any programming language you might learn.

What it means is that with Perl you not only learn the language, but also idioms (usage patterns) and usage of basic libraries.

So you shouldn't try too hard to apply Perl idioms in Java (or the other way round, for that matter) -- that would be very ugly code. Instead you should learn the Java idioms along with the Java language.

That said Java is very different from Perl in many ways; it might be best to forget much of what you've learned, except about the importance of consistent code layout, consistent naming and automated unit tests.