I suggest going to a Python forum, ask how to call Python from a Java program, and in their answer, replace "python" with "perl".

You run the chance the Python people tell you to ask the question in a Ruby forum, and then to replace "ruby" by "python" in the answer you got.

Now, the good people at the Ruby forum will probably suggest you ask the question in a Dylan forum, ....

Or you could just go to a Java forum, and ask how to call external programs.