Hibernate : A J2EE(TM) Developer's Guide

Rating:
Summary: A good introduction to Hibernate
Review: Hibernate is a popular object-relational mapping (ORM) system for Java programmers. As any Java programmer who has worked with a SQL database knows, trying to link Java objects to a relational database is not a trivial exercise. Hibernate simplifies the task by providing an API and a set of tools that can generate Java classes and link seamlessly to a database.

The book starts with an introduction to Hibernate including some details on installation. The author looks at how Hibernate can generate a database schema or it can generate Java classes depending on where you are starting to build your application. XDoclet is discussed with the author pointing out some of the issues with using class annotation. After the introductory chapters, the author gives a good explanation of the details of Hibernate in the middle chapters. The last few chapters look at performance, caching, design issues and other advanced topics. Throughout the book there are many code samples that help to further explain the use of Hibernate.

I do have a few complaints about the book. Although performance is discussed, the cost of using Hibernate on performance is not. I would have liked to see some comparisons of Hibernate versus stored procedures, for example. Also, the weaknesses of an ORM are not discussed. Anyone who has worked with an ORM knows that at a certain level of complexity they start to fall apart and make an application overly complicated. It would have been nice for the author to discuss these issues and at least point towards solutions. Overall, the book serves as a well-written and clearly explained basic introduction to Hibernate.



Rating:
Summary: Too much code
Review: I bought both this book and Hibernate in Action. Hibernate in Action is much better. This book is less informative and devotes far too much space to source code instead of explanation, insight and tips. I don't recommend this book, as there are better alternatives.

Rating:
Summary: quantitative comparisons would help
Review: In writing Java applications that hook to a backend database, using SQL, there is a well known impedance mismatch. Often, using JDBC, you end up embedding scads of SQL strings into your Java code. And then when your code gets a result from the database, you have to finagle this into some object oriented format.

Iverson talks about using Hibernate to handle the two way object/relational mapping. He gives a balanced critique of its merits vis-a-vis the current alternatives of Enterprise Java Beans and Java Data Objects. Both predata Hibernate by several years and have greater mindshare and market presence.

The book goes into the details of the various Java classes that constitute Hibernate. The text is routine here.

What appears to be lacking is a quantitative comparison of Hibernate with the alternatives. A nontrivial proposition, to be sure. But since databases often compete on the basis of various performance metrics, it would also be useful here. Especially because EJBs are considered by some to be really slow. Leaving aside how obtuse EJBs are to program.

The book's message would be strengthened by some credible numbers.