How do I download an jsp file into a pdf with selenium?

I need to download the jsp inside of an iframe using selenium. It has to be in a pdf format.

How do I manage to do this?

<iframe id="miBody" name="miBody" src="/padron-puc-constancia-internet/jsp/Constancia.jsp" height="150%" width="100%" scrolling="auto" frameborder="0" marginwidth="0" marginheight="0" align="top" style="height: 629px;"></iframe>