If you are using some JPA implementation, eg Hibernate, then JPA events are more or less what you are talking about except JPA can't enforce the condition that JPA-defined events are the only triggers present. If you write custom triggers then you run the risk of stale entity data being presented to the user.

But otherwise, this fulfills the condition of triggered events residing in the codebase. Of course, this means you have to be comfortable with using an ORM in the first place.