cpsc2150 Lab 10 Solved

In this lab, you will be working with the Model-View-Controller architectural pattern. While the Model-View-Controller pattern will be beneficial for working with Graphical User Interfaces (GUI), we will not be working with a GUI for this assignment yet. We will be building off the code from a previous lab, specifically the Mortgage and Customer interfaces and classes.

 

Instructions 
 You will need to create a new project with a package called cpsc2150.banking. Add your Mortgage and Customer classes and interfaces from lab 6 to that package. (Note: You will need to create the models folder for these files to match their package structure.) You will then need three more classes:

 

MortgageApp.java 
 MortgageApp will be a very simple class. It will contain our main method that will be the entry point of the program. All it will do is declare an instance of IMortgageView and an instance of IMortgageController, and then call MortageController.submitApplication(). The code should look like this:

 

package cpsc2150.banking; 

 

public class MortgageApp { 

     public static void main(String [] args) {         IMortgageView view = new MortgageView(); 

        IMortgageController controller = new MortgageController(view);         view.setController(controller);         controller.submitApplication();     } 

} 

 

 This type of setup is common when using MVC architectural pattern in Java. We just need the entry point to set up our Controller and View, then turn over control of the program to the Controller.

 

MortgageView.java 
 MortgageView will serve as the View layer of our MVC architecture. That means that MortgageView is the only class that can get input from the user or print to the screen. The Controller layer will use MortgageView to perform these tasks. MortgageView also does not know about our Model layer, so it cannot perform any input validation on whether or not the given values meet our Mortgage or Customer classes' preconditions. MortgageView can still validate whether a "Y" or "N" was entered for yes or no prompts since that is a requirement of the View itself, not the Model.

 The only class-level variables that MortgageView should have are a Scanner object and its IMortgageController object. Remember, we can have issues if we have multiple Scanner objects looking at the same input source, so we don't want to declare one in each function. We actually won't need to use the IMortgageController object, but the initialization ensures clause says we must include it

 MortgageView should implement the IMortgageView interface using a command-line prompt for the user interface. The "get" methods all ask the user for the specified value. They do not perform any data validation (except for validating the Y/N response) as the view does not have access to the Model layer. We can assume the user will input the correct data type (i.e., a number when a number is expected).

                 

Note 1: You may not need to use all the functionality that IMortgageView provides to complete this assignment. That is completely fine; the interface was written to be used for multiple programs, so it may include extra functionality that we don't need right now.

 

Note 2: The IMortgageView and MortgageView files should be placed inside a new views folder to match the package cpsc2150.banking.views.

 

MortgageController.java 
                   The MortgageController class implements IMortgageController and serves as the

Controller layer in our MVC architecture. It controls the flow of control in our program. This class can use both the View and the Model layers to accomplish this task. This class will check to make sure the data that the user provides (through the View layer) meets the preconditions that exist in our Model layer. If the input is not valid, the Controller will (through the View) alert the user to the error and reprompt the user for correct input. The MortgageController class will also use the Model layer (Mortgage and Customer interfaces and classes) to actually apply for the mortgage. After a mortgage has been applied for, the Controller will (through the View layer) display the Customer and Mortgage information to the user (Note: use the toString methods to do this).

 The controller will allow for a customer to apply for multiple loans (without having to re-enter the customer information) and allow for the user to enter information about multiple customers. Remember, the Controller layer cannot directly interact with the user, it must go through the View layer.

 The MortgageController class will have one private field, an IMortgageView object, which is set by an argument passed into the constructor. The MortgageController class will have one public method, called submitApplication() which runs the program.

 All the logic concerning validating the Model's preconditions, and the order of events, is handled by the Controller layer. The logic concerning the Mortgage application or the Customer itself are handled by the Model layer.  

 

Note: The IMortgageController and MortgageController files should be placed inside a new controllers folder to match the package cpsc2150.banking.controllers.

                 

TIPS and additional Requirements
-          You must provide a makefile with make, make run and make clean targets.

o   This will be a large deduction if you do not

-          You do not need to provide any automated testing, although you should test your program.

-          You do not need to provide any contracts for MortgageView, MortgageController, or MortgageApp. Mortgage and Customer should have contracts from a previous assignment.

-          You DO need to comment your code

-          You need to follow the Model-View-Controller architectural pattern for this assignment.

o   All interaction with the user goes through the View layer. View does not have access to the Model layer.

o   Controller layer handles input validation, and the order of events of the program. The Controller layer has access to the View and the Model, so it is the go between for those two layers

o   The Model layer handles our entity objects and the "lower level" logic. It does not have any access to the other two layers.

-          Follow our best practices: No magic numbers, information hiding, separation of concerns, etc.

-          Customer.java has a toString method that will be useful.

-          Make sure your package structure is correct. If IntelliJ / Java gives you an error, check to see if your constructors and functions have the correct visibility!

 

Partners
You are required to work with one partner on this lab assignment. Make sure you include both partners' names on the submission. You only need to submit one copy. Remember that working with a partner means working with a partner, not dividing up the work.  

 


NOTE: Make sure you zipped up your files correctly and didn't forget something! Always check your submissions on handin to ensure you uploaded the correct zip file. 

 

Sample input and outputs: 

What's your name? 

Jim Halpert 

How much is your yearly income? 

-12000 

Income must be greater than 0. How much is your yearly income? 

56000 

How much are your monthly debt payments? 

-247 

Debt must be greater than or equal to 0. 

How much are your monthly debt payments? 

247 

What is your credit score? 

-800 

Credit Score must be greater than 0 and less than 850 

What is your credit score? 

1000 

Credit Score must be greater than 0 and less than 850 

What is your credit score? 

748 

How much does the house cost? 

-120000 

Cost must be greater than 0. How much does the house cost? 

120000 

How much is the down payment? 

-10000 

Down Payment must be greater than 0 and less than the cost of the house. 

How much is the down payment? 

130000 

Down Payment must be greater than 0 and less than the cost of the house. 

How much is the down payment? 

13000 

How many years? 

-15 

Years must be greater than 0. 

How many years? 

30 

Name: Jim Halpert 

Income: $56000.0 

Credit Score: 748 

Monthly Debt: $247.0 

Mortgage info:  

Principal Amount: $107000.0 

Interest Rate: 4.5% 

Term: 30 years 

Monthly Payment: $542.1532815136978 

 

Would you like to apply for another mortgage? Y/N 

y 

How much does the house cost? 

125999 

How much is the down payment? 

12000 

How many years? 

15 

Name: Jim Halpert 

Income: $56000.0 

Credit Score: 748 

Monthly Debt: $247.0 

Mortgage info:  

Principal Amount: $113999.0 

Interest Rate: 4.0% 

Term: 15 years 

Monthly Payment: $843.2368383152977 

 

Would you like to apply for another mortgage? Y/N n 

Would you like to consider another customer? Y/N y 

What's your name? 

Dwight Schrute 

How much is your yearly income? 

73000 

How much are your monthly debt payments? 

...