CS 209 Sec. 52 Spring, 2006 Lab 5: Classes Instructor: J.G. Neal

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1 CS 209 Sec. 52 Spring, 2006 Lab 5: Classes Instructor: J.G. Neal Objectives. To gain experience with: 1. The definition and use of a class to represent a real-world type of entity (an employee). 2. Adding member variables and methods to a class definition (the code for a class). 3. The creation of instances (objects) of a class and the invocation of an object's methods. Notes: 1. For a helpful example of the code for a Java class, see the example class named Person in the instructor s slides for this chapter and the example class named Loan on pages of your textbook. 2. This program for this assignment deliberately does not use any arrays. A real world program would typically deal with numerous Employee objects and would store them in an array. The use of an array of objects will be part of the next assignment. Lab Instructions: 1. Obtain the file named Main.java from instructor's webpage. 2. Create a new project and add the file from instructor to the project. Paste the contents of the instructor-provided file into the default Main class (file) created by NetBeans for your new project. 3. Change only the package name in the Main class (file) provided to you. Use your package name instead of the one in the instructor-provided file. Do not make any other changes to the file. If you do the extra credit portion of this exercise, however, you can also add to the Main class (file) as described in the Extra Credit portion of this assignment instruction document.. 4. Create the Employee Java file. The Employee file must be in your new project mentioned above. It must be in a separate file from the Main class. a. To create the new file, select menu File>New File. In the New File dialog window, select the top choices (Categories: Java Classes; File Types: Java Class), and then click the Next button. In the New Java Class window, fill in the Class Name with Employee (without the quotes) and make sure that the location and package is the same as for the Main file. Then click the Finish button. b. As a result, under Source Packages, you should now have the two files listed within your package folder. 5. Write the code for the Employee class (file). You should follow the instructions listed below carefully, since your Employee class must work with the Main class (file) provided to you. You must use the Main class (file) to demonstrate that your Employee class works correctly. The Employee class must include the following items: a. Private member variable named name of type String. b. Private member variable named idnumber of type int. c. Private member variable named employeetype of type String. d. Private member variable named payrate of type double. e. Private member variable named hoursworked of type double. f. Private DecimalFormat object to format monetary values, as in previous exercises. g. Private DecimalFormat object to format hours worked, as in previous exercise. h. Public default constructor that takes no parameters. This constructor must initialize Page 1 of 5

2 the employeetype variable by assigning it a string value of Generic Employee. i. Public constructor that takes four parameters to initialize the member variables. This constructor must call the default parameterless constructor to initialize the employeetype variable. The order of the parameters must be: String nam, int id, double prate, double hrs. j. A public get method for each of the member variables. Naming convention is to uppercase the firstletter of the member variable and then concatenate the word get on the left end of the variable (e.g., getname, getidnumber, getemployeetype, getpayrate, gethoursworked). Each get method takes no parameters and must return the value of the corresponding member variable. k. A public computepay method that takes no parameters and returns a value of type double. The returned value is the employee s pay, computed by simply multiplying payrate times hoursworked. Do not add a member variable for pay. l. A public tostring method that takes no parameters and returns a string. The string includes the values of all the member variables as well as the employee s computed pay, including the full name of the employee type. The string must include an explanatory label identifying each attribute. All monetary values must be formatted with a dollar sign and two digits to the right of the decimal point. The hoursworked value must be formatted to show two digits to the right of the decimal point. The returned string must not include any line breaks. 6. Compile, run, and debug your program. a. When you compile your program, if you compile the files individually, the Employee class (file) must be compiled first because it is not dependent on any other classes (files). b. The Main class (file) is compiled second because it uses (is dependent on) the Employee class. c. Run the Main file to execute the program. d. Do not run the Employee file. The Main code invokes the methods of the Employee class (file). 7. Run and debug your program. Test and debug your program using a variety of input data. 8. See the example window captures below that illustrate the working program. 9. Create batch file. a. Create a batch file as you did for the previous assignments so that your program can be executed without the use of NetBeans. b. Be sure that the batch file is within your top level NetBeans project folder. 10. Create ReadMe file. a. Using Microsoft Word, create a file named ReadMe. b. In this document, insert your name at the top, and on the next line insert the assignment number. c. Then enter any comments regarding the assignment and your program. d. Indicate whether you did the extra credit part of the assignment. e. Then insert several window captures of windows showing the inputs and outputs from the execution of the program. f. If you did the extra credit part of the assignment, be sure to state this in your ReadMe file. Include additional window captures that demonstrate the extra credit capabilities. g. Be sure the ReadMe document (file) is within your top level NetBeans project folder. Page 2 of 5

3 11. Zip the project folder and all its contents. a. Create a zip file that contains the entire contents of your NetBeans project folder, including all sub-folders and files. b. Your project folder should contain your ReadMe file and batch file, as for previous project assignments. c. Change the name the zip file so that its name consists of your name along with the assignment number, as follows: JohnJones-05.zip. Do not use spaces in the name of the file, use hyphens instead. 12. Extra Credit: a. In your Employee class, write a public set method for each member variable except employeetype. The naming convention is to create a method name for each by concatenating the word set to the variable name, with the first letter of the member variable changed to upper case (e.g., setname, setidnumber, setpayrate, sethoursworked). Each set method must take one parameter, namely the value for the corresponding member variable, and must assign the parameter value to the corresponding member variable. Each set method should return no value. b. Add code to the bottom of the Main class (file) to demonstrate the use of the set methods that you added to the Employee class. Demonstrate the use of all the set methods to change all the values of the variables for at least one of the employees. c. Use a final JOptionPane to show all the data on all the employees after your new additional code has executed and changed the values of all the member variables for the Employee object(s). TO RECEIVE CREDIT FOR YOUR PROGRAMMING EXERCISE: Submit the following for credit to Angel Drop Box for Exercise 05: a. The zip file containing your entire NetBeans project folder with all its subfolders and files. b. You must have a batch file to run your program without using NetBeans, and the batch file must be in your top level project folder. c. You must have a ReadMe file that contains your name at the top, the lab number, any comments regarding the assignment, and window captures to show the program execution. The ReadMe file must be in the top level project folder. d. You must submit your zip file to the Lab05 Drop Box for this CS 209 course in Angel ( DUE DATE: Tuesday, March 7. EXAMPLE WINDOW CAPTURES FOR COMPLETED PROGRAM: Page 3 of 5

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