Programming Project 2 Solution

The second programming project involves writing a program that computes the sales tax for a collection of automobiles of different types. This program consists of four classes. The first class is the Automobile class, which contains the automobile’s make and model, and purchase price, which is specified in whole dollars. It should have three methods:




A constructor that allows the make and purchase price to be initialized.



A method named salesTax that returns the base sales tax computed as 5% of the sales price.



A toString method that returns a string containing the make and model of the automobile, the sales price, and the sales tax, appropriately labeled.



The Automobile class has two subclasses. The first is Electric. It has an additional instance variable that contains its weight in pounds stored as an integer. It should have the same three methods:




A constructor that allows the automobile’s make and model, purchase price and weight to be initialized.



An overridden method salesTax that returns the total sales tax. The sales tax for an electric automobile consists of the base sales tax of 5% that applies to all automobiles minus a discount. If the weight is less than 3000 pounds the discount is $200. Otherwise it is $150.



An overridden toString method that returns a string containing the make and model of the automobile, the sales price, sales tax and the weight, appropriately labeled.



The second subclass is Hybrid. It has an additional instance variable that contains the number of miles per gallon stored as an integer. It should have the same three methods:




A constructor that allows the automobile’s make and model, purchase price and miles per gallon to be initialized.



An overridden method salesTax that returns the total sales tax The sales tax for a hybrid automobile consists of the base sales tax of 5% minus a discount. If the number of miles per gallon is less than 40, the discount is $100. Otherwise there is an additional discount of $2 for every mile per gallon in excess of 40.



An overridden toString method that returns a string containing the make and model of the automobile, the sales price, sales tax and the number of miles per gallon, appropriately labeled.



No additional public methods should be included in any of the above three classes.




Finally there should be a fourth class named Project2 that contains the main method. It should generate the GUI shown below:
































































After entering the information about the make and model, its sales price and the type of the automobile, clicking the Compute Sales Tax button should display the sales tax in the text field to its right. In addition, the object should be stored in an array of type Automobile. That array should allow space for up to the last five automobiles entered.




If non integer values are entering in any of the fields that require integers, an error message should be displayed in a JOptionPane window.




Clicking the Clear Fields button should clear all text fields.




Clicking the Display Report button should produce a report on the console that includes the information about all the automobiles currently stored in the array. An example of the report that should be displayed is shown below:




Make and Model: Toyota Prius




Sales Price: 30000




Sales Tax: 1390.00




Hybrid Vehicle




MPG: 45




Make and Model: Ford Fusion




Sales Price: 21000




Sales Tax: 1050.00




Be sure to follow good programming style, which means making all instance variables private, naming all constants and avoiding the duplication of code. Furthermore you must select enough different kinds of automobiles to completely test the program.

Grading Rubric:




The following grading rubric will be used to determine your grade:




Attribute
Meets
Automobile class
20 points


contains the automobile’s make and model, and purchase


price, which is specified in whole dollars. It should have


three methods:


1.
A constructor that allows the make and purchase price to


be initialized.


2.
A method named salesTax that returns the base sales tax


computed as 5% of the sales price.


3.
A toString method that returns a string containing the


make and model of the automobile, the sales price, and the


sales tax, appropriately labeled.




Electric subclass
20 points


It has an additional instance variable that contains its weight


in pounds stored as an integer. It should have the same three


methods:


1.
A constructor that allows the automobile’s make and


model, purchase price and weight to be initialized.


2.
An overridden method salesTax that returns the total


sales tax. The sales tax for an electric automobile consists of


the base sales tax of 5% that applies to all automobiles


minus a discount. If the weight is less than 3000 pounds the


discount is $200. Otherwise it is $150.


3.
An overridden toString method that returns a string


containing the make and model of the automobile, the sales


price, sales tax and the weight, appropriately labeled.




Hybrid subclass
20 points








contains the number of miles per gallon stored as an integer.


It should have the same three methods:


1. A constructor that allows the automobile’s make and


model, purchase price and miles per gallon to be initialized.


2. An overridden method salesTax that returns the total


sales tax The sales tax for a hybrid automobile consists of


the base sales tax of 5% minus a discount. If the number of


miles per gallon is less than 40, the discount is $100.


Otherwise there is an additional discount of $2 for every


mile per gallon in excess of 40.


3. An overridden toString method that returns a string


containing the make and model of the automobile, the sales


price, sales tax and the number of miles per gallon,


appropriately labeled.




Project 2
20 points


contains the main method. It should generate the GUI


After entering the information about the make and model, its


sales price and the type of the automobile, clicking the


Compute Sales Tax button should display the sales tax in the


text field to its right. In addition, the object should be stored


in an array of type Automobile. That array should allow


space for up to the last five automobiles entered.


If non integer values are entering in any of the fields that


require integers, an error message should be displayed in a


JOptionPane window.


Clicking the Clear Fields button should clear all text fields.


Clicking the Display Report button should produce a report


on the console that includes the information about all the


automobiles currently stored in the array. An example of the


report that should be displayed is shown below:


Make and Model: Toyota Prius


Sales Price: 30000


Sales Tax: 1390.00


Hybrid Vehicle


MPG: 45


Make and Model: Ford Fusion


Sales Price: 21000


Sales Tax: 1050.00




Documentation and Style
20 points
guide




Tests cases provides coverage of code.


Screen captures were provided and labeled for compiling


your code, and running each of your test cases.


Header comments include filename, author, date and brief


purpose of the program.


In-line comments used to describe major functionality of the


code.


Meaningful variable names and prompts applied.


Class names are written in UpperCamelCase.


Variable names are written in lowerCamelCase.


Constant names are in written in All Capitals.


Braces use K&R style.


Declare all instance variables private.


Avoids the duplication of code.