Apprenticeship for what? They want you to build an Oracle interface and no direction was mentioned? What server language does the intranet currently use? What language do you know? What does the network administrator have to say about all this?
There are many possibilities aside from PHP and JSP. If the intranet is currently running IIS (which would be no surprise) then ASP would be a strong candidate. Some people swear by Cold Fusion, Perl is a mature language with strong roots, or even C and probably a few I don't think of right away.
PHP probably has the shortest learning curve, is probably easier to set up on an existing network (in CGI mode at least), maintainance shouldn't be a problem, and it holds its own for performance. It does support Oracle but I have never used it with that database so I cannot comment on usability.
http://www.php.net/manual/en/ref.oracle.php
Security with any language is in your hands.
JAVA is an elegant language but much more complex with a steeper learning curve, maintainance shouldn't be an issue if that is all you are using it for, and it performs well and does play well with Oracle. Installing it should be a breeze. Just drop a note on the IS directors desk saying, 'Please install JAVA', then run like hell.