Hi to all.
since when I upgraded the hibernate3.jar in my java/struts/mysql/tomcat application, I have this error in the stack:


javax.servlet.ServletException: Servlet execution threw an exception
...

root cause

org.hibernate.id.IdentifierGenerationException: no natural-id property defined; need to specify [key] in generator parameters
org.hibernate.id.SelectGenerator.determineNameOfPropertyToUse(SelectGenerator.java:73)
org.hibernate.id.SelectGenerator.access$100(SelectGenerator.java:52)
org.hibernate.id.SelectGenerator$SelectGeneratorDelegate.<init>(SelectGenerator.java:117)
org.hibernate.id.SelectGenerator$SelectGeneratorDelegate.<init>(SelectGenerator.java:98)
org.hibernate.id.SelectGenerator.getInsertGeneratedIdentifierDelegate(SelectGenerator.java:64)
org.hibernate.persister.entity.AbstractEntityPersister.postConstruct(AbstractEntityPersister.java:3145)
org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:439)
org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:84)
org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:272)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1385)


So I tried to replace the slf4j library with other versions, added slf4j-api, slf4j-jdk ,etc but unsuccessfully.
I tried another versione of hibernate3.jar, but the problem stay the same.

Could you please help me?
I don't know what to do.
thanks in advance.

I changed the generator class from "select" to "identity".
Now it works.