Don't worry about it - it's just another language! I'd just like to second the oft-repeated suggestion that you shouldn't write Perl in Java - from personal experience, you'll end up with very messy datastructures which can't be manipulated as easily as they can in Perl. That way lies frustration and hairpulling. Try and pick up the Java idioms, and to really embrace object-oriented programming: it'll make you a better Perl programmer.
I've found that using Google to search directly against the Java API is really good for finding exactly the right method to do something. You might have to try searching by what you want to get done, rather than the name you think the method might have - Java doesn't believe in TMTOWTDI! - and sometimes you'll have to roll your own.
All the best!