SWE 510: Object-Oriented Programming in Java

Due: 11:59 PM, Nov. 11, 2010 
Reminders: Follow the submission instructions. Remember to comment your code!

Total Points: 50

0) Geometry Solver. (50 pts)

   In this assignment you will write three classes that correspond to three
   geometric shapes:  Circle, Rectangle, and Triangle. All three classes
   implement the same interface as follows:

   public Interface Shape {
       public String name();
       public double perimeter();
       public double area();
   }

   The Circle, Rectangle, and Triangle classes will have constructors that
   take exactly one, two, and three arguments, respecitively. For Circle, the
   single argument will be its radius, for Rectangle, the two arguments will
   be its width and length, respectively, and for Triangle, the three
   arguments will be its three sides. 

   To excercise your classes, you will have to provide a driver (main) class
   that asks the user for shape dimensions, and based on the user input, or
   on the number of dimensions given, to be more specific, should correctly
   decide which shape is requested, and print out shape information
   accordingly. For example,

   $ java Shapes
   Please enter shape dimensions: 3.0 5.0 4.0
   Shape is: triangle
   Perimeter: 12.0
   Area: 6.0

   In the driver class, Shape will be used as the base type, and an object
   will be created from on the three classes for initialization based on
   the user input. In other words, you will be using dynamic binding for
   the methods exported by the Shape interface. 

   You have to check the validity of the arguments for shape dimensions. For
   example, the dimensions should be between 1 and 3 (inclusive), the
   dimensions are positive decimal or integer numbers, and that no one side
   of the triangle is larger than or equal to the sum of the other two
   sides. You have to be sure to catch exceptions in reading and parsing
   user input. If the number of dimensions provided is zero or larger than
   3, or any dimension is not recognized as a number, your program may print
   an appropriate error message and exit.

   You can decide where to do your input validation: in the driver or in the
   specific shape class constructors. Commonalities might be better tested in
   the driver, and shape-specific requirements might be better tested within
   the corresponding shape classes. For example, you may decide to test that
   dimensions are valid numbers in the driver, and check positiveness, and
   edge requirements (specifically for triangles) in the shape classes. If a
   shape determines that any dimension is not acceptable, then the shape
   constructor should throw an InvalidDimensionException, which you will
   implement implement, with appropriate error string.

   Based on the arguments given, your geometric shape classes should be able
   to correctly calculate the perimetors and areas of the geometric shapes
   that they correspond to.