Persistent objects stored/retrieved by business layer.

At this level we avoid dependance on specific persistence engines (e.g. Hibernate). We do this by using an interface named {@link org.apache.roller.business.PersistenceStrategy PersistenceStrategy} to store, retrieve and remove {@link org.apache.roller.pojos.PersistentObject PersistentObjects}.

diagram of Roller persistent object and strategy

The diagram below shows the objects in the Roller data model and the relationships between them.

diagram of Roller data model