Great, thanks for the answer about Maven. I use Gradle and am loving it. When I go through your book I am going to try to do everything using Gradle. Can I ask you questions about how to get things working if I have too many difficulties? I have a Gradle book by Benjamin Mushko I will consult first. It has a great section on how to port Maven projects to Gradle projects.
With that in mind, how much does the content of the book depend on using Maven's build system? If I need to I'll use Maven for everything in the book first and then redo everything with Gradle. I don't know much about Maven and I would like to learn how to plug testing into a Maven project.
Here is the link for that book by Benjamin Mushko:
http://www.manning.com/muschko/
I had the good fortune of receiving the book from Hans Docketer during a conference session at SpringOne 2GX in Dallas last year. Gradle seems to be the next step in build system evolution.