APPENDIX DUpgrading from Hibernate 2
Hibernate 3 represents a major change from the ways of doing things in Hibernate 2. On the whole, it is a better product, and we applaud the Hibernate developers for their efforts. One particular group of users will be made nervous by all the changes: the existing users of Hibernate 2.
Well, there is good news, and there is . . . no bad news! Hibernate 3 has gone the extra mile to allow earlier users to get along. In this appendix, we will discuss the differences between the two versions and explain how a Hibernate 2 user can take advantage of them without conducting a major code rewrite.
Hibernate 3 does make changes: the package names have changed, the DTDs have changed, the required libraries are different, ...