CST141 Project 4: Chapter 11

Triangle and GeometricObject classes
--or--
CommunityMember, Student, and Undergraduate or Graduate classes

• Triangle and GeometricObject classes (This is the partial credit assignment worth nine (9) out of ten possible points; you may elimiate the getArea() method for a maximum grade of eight (8) out of ten possible points)

• Start a new Java project named "project-4" and copy into it the SimpleGeometricObject class from Listing 11.1 in the textbook (this class should be renamed GeometricObject) which should be modified as follows
   
  1. Do not assign values to the private instance variables when they are declared
  2. The only statement in the no-argument constructor is a call to the this constructor with default data field values "white" for color and false for filled
  3. The overloaded constructor that takes a String for color and a boolean for filled still instantiates and initializes the dateCreated field but initializes the color and filled fields by calling their set methods
  4. The toString() method substitutes calls to the get methods rather than directly accessing the three instance variables directly
      
• Modify the assignment as follows:
   
  1. The no-parameter constructor only contains a call to the this constructor and passes the default values 1.0 to the overloaded constructor that takes three double parameters
  2. The constructor that creates a triangle with the specified side1, side2 and side3 parameters does so by calling the three set methods; all three set methods should validate that each side is 1.0 or greater
  3. In the getArea() method calculate and return the area of a triangle using "Heron's Formula" given that the length of the three sides is known; the formula can be found by doing an Internet search
  4. The toString() method substitutes calls to the get methods rather than directly accessing the three instance variables and further returns the values from the getPerimeter() and getArea() (unless you choose not to calculate the area--see above) methods; additionally link this method to the toString() method of the superclass to produce output similar to the following (format the getArea() and getPerimeter() method return values rounding them to two decimals using a DecimalFormat object):

     Triangle: side1 = 12.0 side2 = 15.0 side3 = 25.0
area: 63.28 perimeter: 52.00
created on Mon Oct 14 15:30:01 EDT 2013
color: white and filled: false

  5. Create a new class Main and add a main() method that should instantiate two objects, one from each of the two constructors, and display the toString() method return value with either System.out.println() or JOptionPane.showMessageDialog()

• CommunityMember, Student, and Undergraduate or Graduate classes (This is the full credit assignment worth ten (10) out of ten possible points)

• In BlueJ open the Java project named "college" which you downloaded with the "Chapter 11" files from the instructor's website and which already contains the follow class: 

• Then create two class files, a superclass and a subclass, as per the following specifications:

• Both the superclass (Student) and the subclass (either Undergraduate or Graduate) will contain two instance variables (data fields) so that effectively:

1. The Student class will have four fields (firstName and lastName which it inherits from CommunityMember, and the two of its own, studentID and gradePointAverage
2. The Undergraduate or Graduate will have six fields (firstName and lastName which it inherits indirectly from CommunityMember, studentID and gradePointAverage which it inherits from Student, and the two of its own, either satScore and classYear for Undergraduate, or greScore and program for Graduate

• The constructors for the new classes are as follows:

1. The superclass/subclass Student has a single constructor that takes four parameters, two of which it passes immediately to its superclass constructor CommunityMember that takes two parameters
2. The subclasses, either Undergraduate or Graduate, include two constructors: a no-parameter constructor that passes default values (zero (0) for numerics and empty strings for String variables) to the this() constructor and a constructor that takes six parameters, four of which it passes immediately to the superclass constructor of Student that takes four parameters

• All classes should have set methods that contain if validation coding based on the validation rules defined above (there should be a default value for each data field, zero (0) for numerics and empty strings for String variables, to indicate any value is not set) and a get method for each of its instance variables
   
• All classes should contain a toString() method that is a formatted "string" representation of the object with all field values and appropriate labels, and which calls (links to) the toString() method of its superclass

• Document the program using the Javadoc standard by:

1. Including a substantive comment statement that describes the class's purpose, as well as substituting your name for the existing @author comment and the assignment due date for the @version comment that already exist at the top of the new class
2. Entering a substantive comment before each method (including the constructor) to describe its function along with @param and @return tags

• Draw the UML diagram for all classes as specified in the textbook (not for existing superclasses GeometricObject or CommunityMember); it is suggested that you do this before you begin to create the classes as this should make the coding much easier
   
• Create a new class Main and add a main() method to it that includes the test operations as follows:
   
  • Instantiate one object of the subclass using the no-argument constructor; use the showInputDialog() method of class JOptionPane along with appropriate parse methods when necessary to get values to pass to the set methods of the object; display the return value of the object's toString() method in a showMessageDialog()
  • Instantiate a second object of the subclass using the constructor that takes parameters; display the return value of this object's toString() method in another showMessageDialog()

• Students may work on all projects in teams of two or three, and, if so, all students in the group must submit the same project to their own dropboxes in Blackboard.  In the text box's dropbox, as well as in the source code documentation (comments), state the name(s) of the classmate(s) with whom you worked.
   
• When all steps are finished, all Java files:
   
  • All superclasses and subclasses
  • The "Main.java" file that contains the "test" program with the main() method
     
  ... along with the UML diagrams for the superclasses and subclasses are to be submitted electronically via attachments to a Blackboard dropbox is due to Prof. Struck by 11:59 p.m. on the date specified in the course outline.