jdk1.5.0_12
jre1.5.0_12
Hibernate 3.2.2
Hibernate tools 3.2.0
Eclipse SDK
Version: 3.2.2
Build id: M20070212-1330

I have used Hibernate tool for Eclipse to generate hibernate.cfg.xml with successfull, despite that the only driver to MySQL that appear as option is org.gjt.mm.mysql.Driver, but I write manually com.mysql.jdbc.Driver. When the hibernate.cfg.xml is already generated, I go to Hibernate Code Generation option, the problem is in this step, because I'm not able to finish the process, an error occur when I click in refresh, a window "Lazy tree error" with the messages:

org.hibernate.console.HibernateConsoleRuntimeException: Problems while loading database driverclass (com.mysql.jdbc.Driver)
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

I yet add mysql-connector- java-5.0.6-bin.jar in enviroments variables and in the project and path directory but I continue receiving the errors

Sounds like a Class loader problem. Make sure that only one of the Driver classes is available to the application. (via jar file or whatever)

I don't know how much you know about Class loaders so bear with me here. The ClassLoader that physically loads a class is part of the class "signature" for the duration that the class is loaded. If the same class is loaded by a different ClassLoader it is completely different (signature wise) than the first one. So, if an application is looking for the second instance and can only see the first one you'll get your exception because they are different.

read this:

http://www.javaworld.com/javaworld/jw-1 ... depth.html

Hope this helps.

John G.