Repository concept

Repository.java

// It is recommended to use an interface when using a repository. 
// This way you can change the implementation without affecting the usage
public interface IRepository {

    public void connect();

}

public class Repository implements IRepository {
    // get the instance of the controller
    private MainController controller = MainController.Current();

    public Repository() {

    }

    public void connect() {
        // TODO Connect to a database, call an API etc...
    }

    // Other methods ...
}