Decoupling MVC model methods in java

Question

I have a basic swing application that I am trying to develop using MVC structure.

The principal class in the model connects to a derby database and retrieves values from columns and stores them in arrays.

My methods in the model (Connect(), Retrieve()) are public void. In runApp(), which is a SwingUtilities runnable, I am calling my model methods like this:

public static void runApp() {
    Model model = new Model();
    model.Connect(); //Connects to database
    model.Retrieve(); //Retrieves database column values from tables, creates arrays
    View view = new View(model);
    Controller controller = new Controller(view, model);
    view.setCalculateListener(controller);
}

I am trying to write this program so that everything is as less tightly coupled as possible. This code currently works as is, but I would like to do this better.

My question: How can I do this in a less coupled manner? Rather than having the methods being called here, is there a better way to do this?

Answer 1

For starters, consider making Connect() and Retrieve() non-public. runApp() doesn't seem to have a good reason to know about the operations that Model needs to perform to be usable here. Can the constructor (or, possibly more appropriately, a static factory method) hide those methods?

Introducing state to objects is an easy way to make things complicated. If a View or Controller were somehow able to be passed a Model that had been, say, Connect()ed but not Retrieve()d, what would happen? It's simpler to factor that possibility out when that is an option.