You do NEVER call those methods directly, how often do I have to repeat that?

In fact, if you don't understand that you can't even call a private method from another class (or even another instance of the same class) you should not be doing any J2EE stuff AT ALL but start with an introductory tutorial on Java.

You should also do some introductory tutorial on EJBs after that, and one that handles MODERN EJBs, as directly doing JDBC access from entity beans is NOT the way to do things, and hasn't been for years.