In Class Exercise

• This exercise uses UML, Design Patterns (Command), and Exceptions.
• You need a few classes.
• Class WhatDoYouWant is your controller.
• It has public static void main(String args[])
• It takes an input parameter.  This parameter can be Hamburger, Fries, Fresca, or Tab.
• It calls a method, takeOrder(String args[]).  takeOrder instantiates objects that inherit from class Item. You can either use an if test to determine what to instantiate, or use Class.forName().newInstance(), whichever you prefer.
• Class Item is an abstract superclass.
• It has one abstract method, askQuestion();
• Class Hamburger extends Item.
• Its askQuestion implementation has:
• System.out.println("rare, medium, meduim well, or well?");
• Class Fries extends Item.
• Its askQuestion implementation has:
• System.out.println("Light or heavy salt?");
• Class Fresca extends Item.
• Its askQuestion implementation has:
• System.out.println("Regular or Diet?");
• Class Tab extends Item.  It implements askQuestion, but the implementation is empty.
• When the user runs WhatDoYouWant with one of the above parameters, WhatDoYouWant should send the args[] array to method takeOrder(String args[])
• This method must instantiate the object represented in the args[] array.  You only need to instantiate one, but you can handle multiple objects if you wish.
• If the argument is Tab, you must throw an exception.  This code is:
• throw new Exception ("Are you serious?");
• public static void main(String args[]) must have a catch block to handle this exception and print it out.
• For all other objects, run the askQuestion() method.  Hence, the Command Design Pattern!
• Before you write any code, make the UML.  Either with Poseidon or on a piece of paper.
• This is a simple example.  Use if tests if you like, I won't mind.  If you finish early, perhaps add extra functionality (ability to handle multiple arguments, for instance.)
• Ask me if you have questions.

Created by:  Brandan Jones December 17, 2001