The EJB 2.0 Restrictions

Summary

Keep in mind that not all vendors support all of these restrictions, and your EJB server might allow you to use restricted features. For example, WebLogic does not prevent you from doing most of what these restrictions say not to do. This is not true of all the containers and you might lose portability if you violate them.

There are correct ways to achieve the behavior that these restrictions take away. The key is to use the class loader and security mechanisms as designed and know the difference between an EJB-compliant feature and one that is vendor-dependent .