Jakarta ORO just provides perl compatible
regular expressions, it doesn't actually provide any interface to Perl. And for what it's worth, I have found the claim of compatibility to be a little misleading. I was unable to port some of my Perl regular expressions to ORO and had to resort to an ugly set of if/elses. That was before JDK 1.4 was available, I can't recall if I went back and tried to implement the same regular expressions with the native JDK 1.4 support.
I've solved a problem similar to the OP's with a Perl web service called by a Java client, but the performance of SOAP::Lite web services was pretty poor.