INFM 718B
Building the Human - Computer Interface
Fall 2006

Course Description
Syllabus
Reading List
Team Project

Homework 1

Last modified: September 15, 6:26 pm

1. Building the Use Case Diagram (5 points)

Identify two additional Use Cases and one additional Actor for the library catalog system discussed in class. Revise the diagram shown in class to show these. You may sketch this by hand or use PowerPoint (in which case you can extract that slide and use it as a starting point.

2. Building the Use Case Narrative (15 points)

Select one of the Use Cases from part 1 and build its Use Case Narrative. Identify at least 2 ways to end the Use Case.

3. Encapsulating the Book class (15 points)

Parts 3 & 4 should take about 2 hours to complete, but unlike the self-graded assignments you will need to keep at it until you get it right because this one is being graded! Moreover, this estimate assumes that you are caught up on your reading and that you have successfully completed the first two self-graded exercises. You should test your program frequently as you make changes to catch errors early.

Until now, we have let any other class access the instance variables in our Book class. For this exercise, you will enhance the code to properly encapsulate them. Start by downloading the Book.java and BookTest.java files. Import them into your Eclipse workspace using the File/Import wizard, select File system, enter or browse to the directory where you put the files, checkmark the two files, make sure you are importing them into the desired Project folder, and click Finish. (This part isn't graded... send me and the TA email if you have problems.) Now, edit the files as follows:

  1. First, prevent any other class from directly accessing the instance variables by using the private modifier.
  2. Now, create getter, and setter methods for each instance variable.
  3. Change BookTest so that it uses the setter methods to assign values to each field.
  4. Add statements to BookTest (not Book) to display just the title and price of the book, separated by a colon (:). If the price of the book is more than $40, print "Expensive" on the same line.
  5. Add a statement that lowers the price to $28 and then display the book information again.

4. An array of Books (15 points)

The last part of this exercise is to create an array of 3 Books, initialize the array and assign values to each Book, then loop through the array using a for loop to display each of them. Create a new class BookTest2. Use your favorite 3 books for this part.

Submitting your homework

Please print parts 1 & 2 and bring them to class.

For parts 3 & 4 export your 3 files and email them as attachments to both the TA and me (to ensure that one of us gets it). To export a file, use the File/Export wizard. Choose "File System" as the export destination, and click Next. Select the directories (on the upper left) or files (upper right) you want to export and enter or browse to the target directory, and click Finish.

Homework submitted after the deadline (Thursday @ 6:00) will not be graded (since the solutions will be posted), so it is a sure thing that you would be better off to send something on time rather than to sending nothing in the hopes that you might have something better later. And you would be MUCH better off to attend class on Thursday than to skip it so that you can work more on your homework (since you would get a zero on the homework AND miss the class - a really bad deal). Anyhow, you won't know how generous we will be with partial credit until you try! Be sure to read the instructions about working together on homework on the course description Web page if you have any questions about what sort of collaboration is allowed.

Bill Kules