Well I did find one thinko. Your module is named POST::iCrypt but your script uses POST_jCRYPT. Perhaps you have both on your system and are looking at the wrong one? Probably not, but it is worth asking.

Assuming that is not the problem, all that I can really say is that your code looks reasonable to me.

I tried installing Inline::Java on my machine. It failed to pass its test suite. I tried running from the partially installed module but it did not find the MainApplet. I didn't try that hard to debug the issue. (I messed with the CLASSPATH a bit then decided I was putting too much work into it.)

At this point I would suggest asking again. You could ask again here, or try emailing inline-subscribe@perl.org to subscribe to inline@perl.org and ask your question there. I would suggest making your question short to attract more responders. Something like this:

I am trying to call Java from Perl using Inline::Java and am having trouble. In this zip file there is a third party Java library MainApplet.class, there is an example where it is called from JavaScript in MainApplet.html and my attempt to call it from Perl in test.pl. The JavaScript version works but my Perl does not.

Can anyone else replicate this problem on their systems or give me an idea of how to fix it?

That you should at least get someone else to try to download and run it to verify the bug.