The first thing
you should do is drop the 2 from J2EE. Since
Java 5.0, the 2 is dropped from both JSE and JEE.
The most important question is, what skills do you still have? Do you still know
servlets and
JSP? Do you know JPA, EJB, etc?
I do know that JPA and EJB have changed quite a lot. You hardly need XML files for configuration anymore, instead you can use annotations for that.