DAO Naming Conventions

Question

I am developing an application that should establish a connection to the database. To work through this connection, I use the DAO pattern. My question is related to the organization of the code and the name of the interfaces and implementations. The current package structure is as follows:

• mainpackage
• mainpackage.model → Models of each table for creating objects with data from DB
• mainpackage.persistence → ConnectionManager
• mainpackage.persistence.dao → Interfaces and Implementations

I thought about naming interfaces that it would be nice to use something like ClassDAO and DefaultClassDAO for implementation, since I don’t know what to name it. What do you think? Is there any agreement for this?

Answer 1

I would use the agreement described in the "Domain Managed Project" section.

• mainpackage
• mainpackage.model → contains "repositories" as interfaces, such as UserRepository, ProfileRepository, which describe operations for managing your objects in the store (store, find, etc.). This way you don't leak that your repository is a DB.
• mainpackage.model.db (or sql or something else) -> contains SqlUserRepository, SqlProfileRepository implements the interfaces in mainpackage.model and hits DB.

You can even put DB classes in another subproject. I consider it important not to put the database at the center of your design and just consider it as a implementation detail.