This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Struts (both 1 and 2) is a front controller. It has nothing to do with back-end technology like EJB's.
You can use EJB's just like you would with any other program.
We have a Struts-specific forum. I'll move this question there for more input.