Mavs Animal Shelter Software Worksheet

Mav’s Animal Shelter SoftwareDue Tuesday, March 22 at 8 a.m.
CSE 1325 – Spring 2022 – Homework #7 – Sprint 3 – Revision 0 – 1
Assignment Background
This semester we will be developing the Mavs Animal Shelter Software (MASS), which manages a no-kill
shelter aiming to help companion animals of various types to adopt humans. Yes, I have a soft spot for warm
fuzzies. We need to keep track of the animals at our shelter, the human candidates for the animals to adopt,
and the animal – candidate matches made in heaven.
You are encouraged to replace Dog and Cat with other families of animals such as guinea pigs, tarantulas,
snakes, lizards, or parrots.
For the project, we will use a different class hierarchy, with the user interface at root and the data model in
package shelter.
Sprint 3
In this sprint, you will add the ability to save and load your data.
Plan your work in Scrum.xlsx, and include your planning and status information at cse1325/P07/docs/.
In your git-managed cse1325 directory cse1325/P07/, with reference to the UML diagram below, update your
JFrame subclass (that is, your main window) to include File > New, Open, Save, and Save As behaviors. Also
add toolbar buttons for these 4 new features.
• New should create a new, empty animal shelter.
• Open should provide a file chooser dialog, showing only .mass files by default, and when a file is
selected discard any existing data and load the data from the file. Cancel or file read errors should result
in NO loss of existing data and clean recovery.
• Save should save existing data to the most recently opened or saved filename. (You’ll need a new
attribute to retain this filename. I recommend that you store the filename in a String field
Shelter.filename.)
• Save As should provide a file chooser dialog, showing only .mass files by default, and when a file is
selected or a new filename typed in, save existing data to that file. Remember the new filename for
subsequent Save requests.
Update your display after each of these behaviors. While it is NOT required that you ensure no data loss (that
is, discarding unsaved data without warning), it would be a nice touch to obtain user concurrence (think
JOption.showConfirmDialog) before any loss of data.
Don’t forget attributions for any toolbar icons you use!
No new classes are required, but new methods will be created. An updated class diagram is below.
You may adapt code from the suggested solution for Sprint 2, the Nim project from Lecture 14, and the
example code provided in Lecture 14. If your project has serious issues, contact me about baselining the
suggested solution for Sprint 2 so that you can get back on track.
Add, commit, and push all files to your private cse1325 GitHub repository.
Hints
Creating Dialogs
Use the JFileChooser dialog provided by Swing. Lecture 14’s Nim provides a good example. The
recommended file extension is .mass.
File Format
I strongly recommend that you follow the pattern taught in lecture, in which each class is responsible for
saving (via a save(BufferedWriter)) and restoring (via a constructor (BufferedReader)) only its own attributes.
This preserves encapsulation and simplifies your code.
To handle containers such as ArrayLists where the number of elements may vary, first write out the number of
elements, then tell each element to save itself. When reconstructing, read in the number of elements, and then
construct and add that many elements back into the ArrayList.
To handle inheritance, have your superclass save its own attributes. Each subclass should delegate to the
superclass to write and read its own attributes, then follow with the subclass’ attributes.
More complicated is the ArrayList of a superclass type (in our case, ArrayList in class Shelter). As
discussed in class, I recommend that you have each subclass’ save method first write its own family (e.g.,
“dog” as provided by the family() method) out on its own line, followed by its attributes. The Shelter’s
constructor (that is, the superclass constructor) will read this identifier for each element from the
BufferedReader while reconstructing the ArrayList, so that it knows which subclass constructor to call to create
the next object to add to the ArrayList.
Screenshots