Good for beginners.
This is a ideal book for someone starting Java Enterprise Edition (JEE), but also useful for those who want a brief overview of the ne features. It focuses on the changes in version 6 with examples in Glassfish. It also mentioned some of the significant changes in 5 and gives a good high level overview of the JEE platform in general. It also explains things like persistence layer, and ORM.
I’d recommend it to someone who’s new(ish) to java and whats to see what JEE/J2EE is all about. It’s not good as a reference book (but then it’s not pretending to be one.)