CST141 Project 3: Chapter 10

The MyPoint Class

In BlueJ create a new Java project named "project-3" with two classes, MyPoint.java and Main.java:

• Select one of the following full or partial credit projects as per the instructions in the textbook for Exercise 10.4:
   
  • The full credit assignment is to complete the MyPoint class exactly as per the instructions in the textbook with both distance() methods (maximum grade for completing this full credit project is 10 out of ten (10) points)
     
    • The formula for calculating the distance between two points given the x- and y-coordinates of both points is shown in the image below:

                

    • The two versions of the distance() method are as follows:
       
      • Method distance(double, double) takes values for parameters x and y, and calculates and returns the distance between the two points using the formula above
      • Overloaded method distance(MyPoint) takes a parameter value for a MyPoint object, passes its x- and y-coordinate instance variables to the first distance(double, double) method and returns the distance returned from that method
         
    • Hint:  Check the Math class from the Java API libary to find a method that returns the square root of a number
       
  • As an alternative assignment, for the MyPoint class only include the second distance() method, the one that takes the two double parameters x and y and returns the distance from this point object to that of the x- and y-coordinate parameters (this is a partial credit assignment--maximum grade for completing the project with this modification is 9; out of ten (10) points)
     
    • Use the same formula for calculating the distance between two points given the x- and y-coordinates of both points as specified above

  • If you feel that the formula to calculate the distance between two points is too complicated, you may eliminate both distance() methods from your MyPoint class for an additional one-and-one-half (1½) point deduction (maximum grade for completing the project with this modification is 7½ out of ten (10) points)
     
  • Additional instructions for any of the MyPoint class options:

• The two instance variables, x and y, are both type double
   
• There should be two constructors, the first which makes a call to the this constructor and creates a default object with default values; since there is no mention of set methods in the textbook assignment, assign the values of the x and y parameters directly to the instance variables in this second constructor, e.g. objects instantiated from the class are immutable (there is no validation required for x and y since negative values are valid for both coordinates)
   
• All statements in the class that reference data members (e.g. in the distance() and toString() methods) should call the get methods of the classes (do not reference data members directly which is the Java standard)
   
• Include a toString() method that returns a String representation of the class which should be a formatted representation of the x and y coordinates in the format (assuming that the current instance variable values are x = 10 and y = 30.5):

  MyPoint coordinates: x = 10.0; y = 30.5

• Within class Main in the main() method include the following test operations:
   
  • Instantiate two objects of the class, one using the no-parameter constructor with default values zero (0) for both the x and y instance varibles and the other that passes actual values to the second (double, double) constructor
  • Use the showMessageDialog() method of class JOptionPane to display the return values of the toString() methods of both objects; additionally in the showMessageDialog() call the distance() method with a descriptive label depending upon which version of the project you are completing; for example:

    MyPoint coordinates: x = 0.0; y = 0.0
MyPoint coordinates: x = 10.0; y = 30.5
Distance: 32.0975


• Document all classes using the Javadoc standard by including:
   
  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 the class as specified in the textbook; it is suggested that you do this before you begin to create the class as this should make the coding much easier; the instructor will not give you any help with your project until the UML diagram is completed.

• When all steps are finished, you will submit two Java files, the "MyPoint.java" class file and the "Main.java" file that contains the "test" program with the main() method
   
• 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.
   
• The completed project with a copies of class files (the .java files) along with the UML diagram 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.