This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
You don't need prior knowledge of Struts 1, but you do need to know OOP and Java. Knowing the Servlet API is definitely a plus even though a Struts programmer rarely has to write a servlet anymore. JSP is optional because Struts 2 supports other technologies for the view.