Hibernate annotations and dialect propert in persistence.xml is enough for Hibernate to generate tables?
Yes, Hibernate works by itself, Spring just helps Hibernate to provide a data source and help you to access to the Hibernate API.
there must be something like Spring to look for annotations and fire a generation event and start some other things?
Nope, that's Hibernate work as well, just by adding hibernate.hbm2ddl.auto
property. This is explained here: