shenyilu / practice.cardb

Car Database Practice

This is not a required assignment.

In this practice assignment, you will practice using the following:

• Interfaces
• Inheritance
• Arrays

Overview

For this assignment, you will build a database using the following CSV file: cars.csv. You will then implement a driver class that invokes methods to retrieve required information from the database.

If this were a graded assignment, your grade will depend heavily on the design of your solution. Make sure that all of the requirements are followed and that the remaining components are well-designed and efficient.

Design Requirements

Your solution must use the following design elements.

You may not use ArrayList for any portion of this program.

You may not use ArrayList for any portion of this program (REALLY!).

Car

You must implement a base class Car. The Car class cannot be instantiated. A Car must have at least the following properties:

• model (column Model)
• vehicleClass (column Veh Class)
• pollutionScore (column Air Pollution Score)

Car must also be Comparable. Car objects are sorted first by pollution score. If two Car objects have the same pollution score then they will be sorted by model.

GasCar

GasCar is a subclass of Car.

A GasCar is any car that does not have a Fuel of Hydrogen or Electricity. Hybrid cars (e.g., Fuel Gasoline/Electricity) are considered type GasCar. GasCar must have at least the following properties:

• numberCylinders (column Cyl)
• mpg (column Cmb MPG)

For cars with two values for Cmb MPG the value used should be the first value (to the left of the "/").

GreenCar

GreenCar is a subclass of Car.

A GreenCar is a car with Fuel either Hydrogen or Electricity. GreenCar will have one property:

• fuelType (column Fuel). This will either be "Hydrogen" or "Electricity".

CarList

CarList maintains a sorted array of Car objects. Use the compareTo method to sort Car objects. You may not use Arrays.sort in this method.

CarList will have, at minimum, the following methods. You may add additional helper methods as appropriate.

Method	Description
addCar	Takes as input a Car and inserts it into the array in sorted order. If the array is full it will be resized to accommodate a new item. If two Car objects are equal according to compareTo they will be sorted in the list in the reverse order in which they appear in the original data file.
toString	Returns a String representation of the entire database. The representation of a GasCar will look as follows: Model: VOLVO XC 90 Class: standard SUV Pollution Score: 9 MPG: 25 Cylinders: 4 The representation of a GreenCar will look as follows: Model: FIAT 500e Class: small car Pollution Score: 10 Fuel Type: Electricity
toStringGreenCars	Returns a String representation of the GreenCar objects in the list where the representation for each Car is of the following format: Model: BMW i3 BEV Fuel Type: Electricity Note, the format for this method is different than that of the toString method.
avgMpg	Takes no parameters and returns the average MPG across all GasCar objects.
avgMpgByPartialModel	Takes as input a String with a partial model (for example, "Subaru") and returns the average MPG for all cars with a model containing the partial model query String. You may use the String contains method in your solution for this method.
findClassesByCylinders	Takes as input an int specifying number of cylinders and returns a String[] containing the vehicle classes with models that have the specified number of cylinders. For full credit, the String[] will have no repeated elements (each class will only appear once) and the length must be large enough to accommodate only the number of valid elements. The resulting array will be sorted and you may use Arrays.sort for this purpose.
findModelsByClassAndMpg	Takes as input a target vehicle class and a minimum MPG and returns a String[] containing the models of all vehicles of the specified class that have at least the specified combined MPG. The String[] may have repeated elements if the same model appears twice in the dataset, but the the length must be large enough to accommodate only the number of valid elements. The resulting array will be sorted and you may use Arrays.sort for this purpose.

CarDBDriver

The main method will be in a class called CarDBDriver.

The main method will expect four command line parameters. The first will be the -in flag. The second will be the relative path to the csv file to be processed. The third will be the -out flag. The fourth will be the name of the file where the output described below will be saved.

	 * Expected usage:
	 * 	java practice.CarDBDriver -in <relative path to cars.csv> -out <output file name>
	 * 
	 * Example:
	 *  java practice.CarDBDriver -in cars.csv -out actual.txt

The suggested algorithm for this method is as follows:

• Build a CarList object from the file cars.csv.
• Output "All Cars:" followed by a newline.
• Output the result of calling toString on the CarList.
• Output "Green Cars - Fuel Type:" followed by a newline.
• Output the result of calling toStringGreenCars on the CarList.
• Output "Average MPG All:" followed by the result of calling avgMpg on the CarList followed by a newline. The result should be displayed with exactly two digits after the decimal point.
• Output "Average MPG Subaru:" followed by the result of calling avgMpgByPartialModel("SUBARU") on the CarList followed by a newline. The result should be displayed with exactly two digits after the decimal point.
• Output "Average MPG Toyota:" followed by the result of calling avgMpgByPartialModel("TOYOTA") on the CarList followed by a newline. The result should be displayed with exactly two digits after the decimal point.
• Output "Average MPG Ferrari:" followed by the result of calling avgMpgByPartialModel("FERRARI") on the CarList followed by a newline. The result should be displayed with exactly two digits after the decimal point.
• Output "Vehicle Classes with 4-Cylinder Cars:" followed by a newline followed by the result of calling findClassesByCylinders(4) on the CarList. For each item in the list returned, output a tab followed by the item followed by a newline.
• Output "Vehicle Classes with 6-Cylinder Cars:" followed by a newline followed by the result of calling findClassesByCylinders(6) on the CarList. For each item in the list returned, output a tab followed by the item followed by a newline.
• Output "Small SUVs with MPG > 22:" followed by a newline followed by the result of calling findModelsByClassAndMpg("small SUV", 22) on the CarList. For each item in the list returned, output a tab followed by the item followed by a newline.
• Output "Small Cars with MPG > 35:" followed by a newline followed by the result of calling findModelsByClassAndMpg("small car", 35) on the CarList. For each item in the list returned, output a tab followed by the item followed by a newline.

Additional Requirements and Hints

Your output must exactly match the following: expected.txt All spacing, indentation, and ordering must exactly match the result. The CarDBTest case will not pass unless your output matches exactly.

You may implement classes in addition to those specified.

It is strongly advised that you do not open the cars.csv file using another program like Excel. It can change the formatting when resaving causing problems with your solution. Instead, create a copy of cars.csv and open the copy as necessary.

Refer to the guide for setting up your development environment as well as the easy practice assignment as necessary.

Submission Requirements

1. Use the following link to create your private github repository for this assignment. The repository will be seeded with the skeleton code, test cases, and input files. CarDB Practice
2. For full credit, make sure to follow all Style Guidelines. Points will be deducted for each violation.

Grading Rubric

This is an ungraded assignment. For most assignments, the rubric will specify the number of points awarded for passing each set of test cases, the number of points awarded for passing additional test cases not provided, the number of points for design, and the number of points awarded for following the style guidelines as described above.

Partial credit may be awarded for partial functionality and/or partially correct design or style elements.

Academic Dishonesty

Any work you submit is expected to be your own original work. If you use any web resources in developing your code you are required to cite those resources. The only exception to this rule is code that is posted on the class website. The URL of the resource you used in a comment in your code is fine. If I google even a single line of uncited code and find it on the internet you may get a 0 on the assignment or an F in the class. You may also get a 0 on the assignment or an F in the class if your solution is at all similar to that of any other student.