Question

I’m using this tutorial: http://www.objectdb.com/tutorial/jpa/eclipse/ee/ejb

Is the persist function required? The class isn’t extending any other classes.

Is DAO required in my model name? I see List<Guest> is <Guest> referring to GuestDao or the package name? If I had to guess I’d say GuestDao

Thanks for clearing this up

Answer 1

The persist method is a type-safe persist method. It can cut down one type of programming error (saving the wrong entity type through the DAO).

It’s required in the sense that a GuestDao would be expected to have Guest-specific methods.

It also keeps knowledge of the persistence mechanism itself out of the mainline code: separation of concerns. All the mainline code needs to do is persist guests via the DAO.

Dao is not required in the model name. It would actually be confusing, since it wouldn’t be a DAO. Guest refers to a guest. GuestDao refers to a DAO for Guests.

List<Guest> refers to a collection of guests. List is a generic type, the symbol between the "<>" is the collection type, in this case, Guest. Guest refers to exactly that–the Guest class.