Homework 1. CS4240 Principles of SW Design
Last modified: Sept. 2, 2010,
an existing SW application to learn about the structure of its design.
Also identify any code smells or other design flaws that you
discover. Document the results.
Learning objectives for this homework:
When Due: Weds., Sept.
15, 11:30pm. Submit this to the ITC Collab site for the
course. Late: 10% penalty per day, up to two days late.
- Become more comfortable reading and studying code in large
- Gain experience thinking of software organization at a
higher-level than just classes.
- Review your understanding of inheritance and its role, and also
get experience in drawing UML class diagrams with a tool.
- Apply what you've learned about code-smells to find problems in
an existing system.
- Gain experience describing SW designs to others in writing and
You may work in pairs but each person must understand all aspects of
the solution. Teach each other; don't simply divide and conquer.
What to do:
Choose one of the SW applications available for this assignment.
Each has been stored so that it can be unzipped and then imported
as a project into Eclipse. (You can use another IDE to explore
this code, but we'll assume you're using Eclipse since it has some nice
features for working with large projects with many files.) If you
have some other application you want to use, that's possible -- contact
2) High-level Structure:
the code and see if you can identify any organization at a higher level
than the class level. If the code is divided into packages, see
if you can describe each package in terms of its purpose and what it
contains. Don't just list the classes in it; try to understand
the package as a subsystem or a organizing-unit at a higher-level of
abstraction than a set of classes. If you see things inside the
package that seem out of place, note those. If there is not a
good package structure, see if you can identify some relationships
among the classes that gives some kind of logical organization to the
system. (For this part, don't look at inheritance relationships. See
3) Inheritance Relationships:
and document inheritance hierarchies in the code. (If there are a
lot of these, identify two important ones and just document those.)
For the documentation, write a short paragraph describing each
hierarchy's purpose and role in the system, and what abstractions it
tries to capture in its superclass(es). Comment on any problems
you see in this use of inheritance, if any are obvious. Also, draw a
UML class diagram of each hierarchy you document using the Violet UML
(Or anything else, but Violet is easiest. Later we'll use a more
professional UML tool, and if you want to start with that and not use
Violet, ask me for details. Keep this diagram very
simple by not including any fields or methods (though you can if you
(Link to the Violet tool.)
4) Code Smells:
to sniff out at least three different code smells or other low-level
design or coding problems in this system. Don't simply look for
the bad coding problems (e.g. bad comments, bad names, bad formatting,
etc.) but instead look for design-level issues as discussed in class.
If you find problems, suggest solutions. (You don't have to
change anything or turn in better code.) Write up what you've
found, and cut-and-paste code from the SW app to show what you've found.
Note: If the system you have seems to be of high quality and doesn't
have code smells, then choose at least three examples of methods or
classes that you think do exhibit good software design
properties. Explain why. If you choose a method, you must
pick some of the larger or more complex methods in the code. (No
points for explaining why a getter method is well designed!)
a link on Code Smells -- look for some of these related to design.
Better info on Code
Smells is found in Robert Martin's book Clean Code in Chapter 17. See
the link on the Resources page of the class website.
5) Design Report:
the results of 2, 3 and 4 above in a Word or PDF document that I can
read. At the top, state what system you're reviewing and the
names of your team members. Turn this in using the submission
system by the deadline. In this document, you do not have to
write long reports or wordy descriptions as long as you cover the
points above. Imagine you are writing for your manager who needs to
understand clearly but is also very busy.
6) Part 2: JUnit and Ant
We will ask you to create some JUnit tests for the system you study (or
one of the others), and also to learn the basics of the Ant build
tool. Each person will do this part on their own. We are
working on the details (Ant tutorials, directions for what to do, how
to demonstrate this works, etc) and will let you know as soon as we've
worked it out. (Part 2 may have a different due date. It's
worth no more than 30% of the total assignment, perhaps less.
Systems: Other software
systems may be added to this list. If you want to suggest or
contribute, one let me know!
The following should (I think) be "importable" into Eclipse by clicking
Import on the File menu (or right-click the Package Explorer).
- eeclone: a simple game where you blow things up!
Download Zip file from the Files page.
Run it using EEClonePanel.main()
More info on this app is here.
- RealEstate: a Monopoly-like game
Download Zip file from the Files page
Run it using Main.main() in package edu.ncsu.realestate.gui.
- Tyrant: is a graphical "rogue-like" fantasy adventure game.
Download Zip file from the Files page.
Run it using QuestApplication.main() in package mikera.tyrant
(Yikes! Currently fails as of Sept. 2. Stay tuned.)