Looking at MasonX::Lexer::MSP i'm guessing that you want to use Perl "inside" XML/HTML - you can look at Text::Template, Apache::ASP or PLP.

I wouldn't recommend any of them for bigger applications, though, just as I probably wouldn't recommend using "plain" JSP in big Java web-app either. I'd go for HTML::Template or Template::Toolkit, (possibly combined with Maypole or CGI::Application, because they "force" you to split up representation and application logic, so your application has a much better chance of staying maintainable.

I can ofcourse be wrong in my interpretation of your question, so:

If you want to call Java from Perl, you might want Inline::Java. If you want to call Perl from Java, take a look at this post.

What do Ant and DBI have to do with JSP?