> I need to load/unload jars dynamically, and I don't
> know how do that...
Try using a classloader ...
need more info. What classloader scope? server? app? When? Why?
in 2.4 you can use an ear or maybe the j2eescopedDeployer to reversibly load app-scope jars.
in 3 you can use sars or classpath refs from a --service.xml file. There are lots of examples in the 3 distro and lots of discussion/arguments on the dev list.