This is the situation:
I have a J2EE application, when there is the first call to Hibernate I build a configuration object, from which I build a sessionFactory object which I store in JNDI ... this first step maps all the classes (and of course is quite slow)
On the second call I get my session factory from JNDI ... and everything is fast.
My problem is that I have to add a new class to map a run time, after the configuration object is build and throw away ...
I've seen that sessionFactory has the evict method to remove an old class, but how can I add a new one?
Should I keep in some cache the configuration object and make a new sessionFactory from this one (after adding the new mapping)? Is this a dangerous operation to make while the application server is working, and so there are many other users who calls hibernte fuctions?
Any help will be appreciated
Regards
Alessandro Rizzi

Session factory is "immutable" considering the mapping configuration, you have to build a new one.
.evict() is here to clear the cache, not to change the mapping configuration.