Assignment 2 Entity Classes

CMPT 270

Developing Object Oriented Systems
Assignment 2
Entity Classes
 Total Marks: 112
General Instructions

• Programming questions must be written in Java.
• Non-programming questions must be submitted as either .txt or .pdf ?les. If other ?le types
are used, you will receive a grade of zero for that question.

Question 1 (112 points):
Purpose: Practising Object-Oriented Programming
Degree of Di?culty: Tricky
For this question, you must implement three classes: a Person class, a BasicDoctor class, and a Ward class.
Each class should have a constructor, as well as the instance variables and methods speci?ed below.
For each of the classes, all the instance variables should be declared as private. Be sure to follow the
speci?cation given below, since the classes will be used in subsequent assignments in order to build a
simple hospital management system. In addition, each class is to have a static main method that should
be used to test the class methods following the principles of testing as discussed in class.
Note from your instructor: This assignment is big. I would highly recommend you employ the test-driven
development strategy you used in CMPT 145. It will save you a lot of time and unnecessary e?ort debugging later on.
(a) (24 points) The Person class. This class models a person. For our purposes, a person will have the
following features:
• A name
• A health card number
• A constructor that takes in the person’s name and health card number
• An accessor method for the name
• A mutator method for the name
• An accessor method for the health card number
• A toString() method that returns a string representation of all the information about the person in
a form suitable for printing
• A main method that will test all of the above features
(b) (18 points) The BasicDoctor class. This class is the representation for a doctor. While it is anticipated
that a doctor will have a number of attributes that could be stored, we will keep this basic version very
simple. It will have the following features:
• A name
• A constructor that takes in the doctor’s name
• An accessor method for the name
• A mutator method for the name
• A toString() method that returns a string representation of all the information about the doctor in a
form suitable for printing
• A main method that will test all of the above features
(c) (46 points) The Ward class is represents a physical ward in a Hospital (like the emergency room). It will
have the following features:
• The ward name
• The integer label of the ?rst bed
• An array that stores the people in the beds of the ward (this will be modi?ed to a Container Class
in a later assignment)
• A constructor that takes in parameters for the ward name, the ?rst integer label for a bed in the
ward, and the last integer label for a bed in the ward; See the section below titled “Additional
Information" for more insight into how the bed labels should work

• An accessor method for the ward name
• An accessor method for the ?rst bed label
• A method that returns the last bed label
• A method that converts a bed label to its corresponding array index
• A method that converts an array index to a bed label
• A method that checks to see if a particular bed label is occupied
• A method that gets the person at a particular bed label, the bed must be non-empty
• A method that assigns a person to a particular bed label, the bed must be empty
• A toString() method that returns a string representation of all the information about the ward in a
form suitable for printing including the name of the ward and for each bed:
– the bed label (if the bed is empty) OR
– the bed label and the name of the person in the bed
• A main method that will test all of the above features
hint double[] example = new double[10]; will create an array of doubles with size 10.
(d) (24 points) You will need to include internal and external documentation with every class. See below
for what is expected:
• Proper internal documentation includes:
– A comment just before the class header that gives an overview of the class. For example, if
the class models an entity, the comment might state what entity the class models and specify
the key features. Alternatively, if the class serves as a container, state what type of items the
container stores, and how these items are accessed. If the class is an interface, state what it
provides an interface for and whether there is anything special about the interface. Finally, if
it has a control function, what is it doing and controlling? Recall that comments for a class
appear before the class and begin with /**.
– A comment just before each instance variable stating what is stored in the ?eld, again beginning with /**
– A comment before each constructor and method stating what it does. Note that the comment
only gives what the routine does, not how it does it. If it isn?t obvious from the code how it
accomplishes its goal, comments on how it is done belong in the body of the method.
– Single line comments as needed to improve the readability of your code. Over-use of singleline comments will result in a deduction of marks.
– Use descriptive variable names and method names.
– Include good use of white space, especially reasonable indentation to improve the readability
of your code.
– Hard-code all of the data for your testing. Minimize console input and output by only reporting
errors(These are the same principles we applied in CMPT 145).
• External Documentation:
– A description of how to execute your tests of the classes. What is necessary to compile your
classes? What program or programs need to be run to show the execution of your program?
For example, it might be necessary to compile and execute all three classes individually. On
the other hand, you might have written a driver program (another class with a static main
method that invokes the main methods of the three required classes; the static main method
of class A can be invoked by A.main(null);). In the latter situation, we need to know the name
of the driver class. This description should be very short.

– The status of your assignment. What is working and what is not working? What is tested and
what is not tested? If it is only partially working, the previous point should have described how
to run that part or parts that work. For the part or parts not working, describe how close they
are to working. For example, some of the alternatives for how close to working are (i) nothing
done; (ii) designed but no code; (iii) designed and part of the code; (iv) designed and all the
code but anticipate many faults; or (v) designed and all the code but with a few faults; (vi)
working perfectly and thoroughly tested.
– Maintenance manual. This is information for the person or persons who must keep your system running, ?x any faults, and do any upgrades. The reader of the maintenance manual is
expected to have the same background and experience as yourself, but of course not having developed your system. This part of the documentation will vary from assignment to assignment. For this assignment, it is su?cient to include a UML class diagram showing all the
features of each class, and the relationships (inheritance, uses and aggregation) amongst the
classes (if any).
– UML diagrams should be generated with a program like UMLet or an online tool, such as
https://www.gliffy.com/uses/uml-software/. Make sure that you use the correct arrows and
arrowheads. Incorrect arrowheads will lose several marks. You can also draw out a UML diagram by hand and scan it. Just make sure it is easily readable.
Additional information
Bed Labels As further information about the integer labels of the beds, suppose that the ?rst bed has label
200 and the last one has label 250. Recall that in Java, the indices of an array always start at 0. Thus, the
array indices will be 0, 1, 2, ..., 50. In addition, integer bed label 200 will need to map to array index 0, 201
map to 1, etc. All classes outside the Ward class will specify a bed by its integer label (say 200 ... 250),
while the Ward class must also deal with array indices. All the complications in dealing with array indices
should be within the Ward class. Hence, if later a more complex scheme is used to label beds, all the
changes to convert the new labels to array indices will be in the Ward class.
Assignment Scope The above classes are simply entity classes for use in a larger system. A hospital
application would have a whole other part (perhaps quite large) to obtain information and requests from
users, to determine what operations are to be done, to carry out those operations by invoking methods
of the entity classes, to return appropriate information back to the user, etc. Later assignments will ?ll in
these parts. You do not need them for this assignment.
What to Hand In
• The completed Person.java program.
• The completed BasicDoctor.java program.
• The completed Ward.java program.
• a2q1_documentation.pdf that contains the external documentation for each class and the application
as a whole. Any documentation relating to a speci?c class should be easily identi?able.
Be sure to include your name, NSID, student number and course number at the top of all documents.
Evaluation
In each class, the following evaluation scheme is used:
2 pts For each instance variable

2 pts For each method
2 pts For testing each method
3 pts For internal documentation
5 pts For external documnetation
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