Updates
Latest Tweet
What's New?
Check out for latest innovation, a computer based training video collection
Like this Page
Java Data Objects Review by Damon Clinkscales
A good introduction to JDO
Java Data Objects by Robin M. Roos is one of the first books
available on the subject of JDO. The author does a good job of
explaining the impetus for the creation of JDO and the concept
of transparent persistence. The first 200 pages of the book are
effective at presenting the meat of what JDO is about in a way
that is more readable than the JDO specification of about equal
length. If you like reading specifications, then you probably
wouldn't buy this book anyway. For Java architects, designers,
and programmers looking to understand JDO, this book is a good
start. It is assumed that the reader has a background with Java
development, but not necessarily persistence methods. Of course,
Chapter 11's discussion of JDO and J2EE will make more sense if
you are familiar with the J2EE.The book has a good flow and an easy to read style (I love the
occasional use of "whilst", but maybe that's just me). Java Data
Objects succeeds for the most part in not relying on any forward
references. The only one I remember was the concept of "fetch
groups", which isn't defined until pg. 156. It also does a good
job of staying vendor neutral and presenting the technology as
defined by the spec. The author was careful to point out vendor-
dependent features. I enjoyed the careful use of UML, state
transition, and object interaction diagrams in the text to explain
key concepts. Particularly, chapters 4's explanation of an
object's lifecycle and chapter 5's description of the persistent
object model. Chapter 6 is a walkthrough of the most commonly
used JDO classes and interfaces.The book is well written and easy to follow. For the architect,
designer, or developer considering new ways to persist objects
(in a relational or object db), JDO is definitely an interesting
new alternative to consider. I had a few issues with the
examples and the CD, but frankly I didn't want to spend a lot
of time learning different product environments at the time I
was experimenting with the examples. Here's a suggestion: why
not include the JDO RI from Sun on the CD? It might be nice to
provide a set of scripts which use the reference implementation
as an alternative to the commercial offerings.