If you need to use EJB and JCA you will need
to put some of J2EE APIs here to compile WSIF
with support for J2EE.

For example see: http://java.sun.com/j2ee/download.html
and put j2ee.jar here

NOTE: to compiel JCA sample it is required to use J2EE 1.3.1
and not newer 1.4 as there were incompatible changes.