Seems to me that there's a small bug in this:
<set name="events" table="PERSON_EVENT">
<key column="PERSON_ID"/>
<many-to-many column="EVENT_ID" class="Event"/>
</set>

I think "Event" must be changed to "events.Event" for the code to work.

hibernate uses reflection to identify the class from name . hence this doesnt seems to be a bug :)

but the code did not compile until I made this change... so I think it really is a bug. It's true I think that the class name is Event; you seem to be saying that Java can map from Event to know that the class is in package events.Event. That does make sense, however, it doesn't compile. When this same construct is used elsewhere in the tutorial, the class (Person, I think) is qualified with the "events." package name.

Another little thing - the tutorial says you need to locate library sdk.jar (servlet developers kit), but I found that it did not seem necessary to find and download this library; also, I was not able to find the library, anyway.

The tutorial is great; I'm not complaining, just trying to help out.

Did you miss the package attribute?
<hibernate-mapping package="events">
Normally it is quite useful.

Regards Sebastian

That's true that use of the package attribute would have taken care of it, but this tutorial doesn't introduce/use package attributes in xml files. Anyway, I noticed that some industrious person seems to have taken care of this little thing; someone changed "Event" to "events.Event" where it needed changing. Thanks! :)