Question

How are models and DAOs supposed to interact? I’m in the process of putting together a simple login module and I’m unsure where to put the “business logic.” If I put the logic with the data in the model, how would I access the logic?

Currently, I have:

1. A controller that receives form data
2. A model that is a simple reflection of a db table
3. A DAO that using hibernate performs a simple select query, based on the
   form parameters received by the
   controller.

Answer 1

The controller has to find/load the business object matching the request and execute it. The Strategy Pattern is useful in this. The business object on its turn has to get a handle of the DAO and the model to do the process.

E.g. (pseudo, inside a front controller servlet)

public void process(request, response) {
    View view = new View(request, response);
    Action action = ActionFactory.getAction(request);
    if (action != null) action.execute(view);
    view.navigate();
}