Ch 3 Lab: The Invoice Class

An Invoice object maintains information about the purchase of some software and is capable of printing an invoice of a customer's purchases from the Acme Software Company. Design and implement an Invoice class. Here are some additional specifications:

Instance Variables: The Invoice class should have instance variables to represent the customer's name and the name of the software that is being purchased.
Constructor Method: A constructor method should allow the customer's name to be set when an instance of this class is created.
Instance Methods: The Invoice class should include mutator and access --set() and get()--methods for each of its instance variables.
Output Method: The Invoice class should contain a print() method that prints a hard copy of the invoice. Note that all software titles marketed by Acme cost $99.00, which makes it easy to calculate the total purchase price. Here's a sample of a printed invoice:
```
-----------------------------------
Acme Software Invoice
Customer Name: Trinity College
Software Title: Chess for Beginners
Aount due: $99.00
-----------------------------------
```

Problem Decomposition

This problem can be divided into one class, the Invoice class, which will contain the instance variables and methods described above. Include a main() method in the class so that you can create Invoice objects that can be used to test your set() and get() methods.

Design

Draw a UML class diagram of the Invoice class, showing all of the instance variables and methods, including their accessibility (public or private) and data types (String).
Step 2. Develop a written specification for the Invoice class based on your UML diagram. This will become a comment block at the beginning of your source file.
Create a CodeWarrior project named Lab3, using the Java Application Stationary, and saving the project on your desktop. Don't forget to rename the TrivialApplication class to Invoice and make the corresponding change to the name of the Java source file and to the project's target.

Implementation (Stepwise Refinement)

Code the initial comment block (purpose of your program, your name, lab section, etc) and the basic class definition.
Code the declarations for the class's instance variables as well as the constructor method.
Add code to the main method to create and use one Invoice object.
Add code to the main method to create and use a second Invoiceobject.

Optional

This section is required if you complete all other lab activites before 3:30 PM.

The Acme Software Company's product line has expanded to the point where it is no longer feasible to charge $99 for every software title. Modify the Invoice class to keep track of the price of the software title. This will require an additional instance variable and additional mutator and accessor methods. Modify the print() method to reflect this change. For example, after this modification, the following invoice should be possible:

-----------------------------------
Acme Software Invoice
Customer Name: Trinity College
Software Title: Chess for Experts
Aount due: $198.00
-----------------------------------

Lab Checkout

Have your work checked by the lab instructor before you leave the lab. Make sure to include your name and the lab section in files.

Hand in your file: Invoice.java.