Fleet Continued

We continue our motor pool development. This class uses the Car class we wrote previously and extends the Fleet class.

What now?

This lab adds a single method to the Fleet class you wrote previously. Here it is:

ArrayList getSortedByMPG() // returns a copy of the fleet's list of cars sorted by MPG (with the worst MPG car first, the best MPG car last). NOTE THIS IS AN ACCESSOR. Include sorting code in your class; the Selection Sort code in the Arrays chapter may help. Also note that ArrayList has a constructor that will take a "Collection" to supply the elements of the new ArrayList. An ArrayList is a Collection, so that constructor may help. You may also wish to review the video(s) on the Object Memory Model that covered aliases. Do not use language elements that we've not covered.

tester:

A tester is in the attached zip file.

Grading Elements:

class name, all constructors, all method names, all method signatures and return types are correct

ArrayList getSortedByMPG() returns an array list of all the cars in the fleet with the worst-MPG car first, and the best-MPG car last. This method leaves the fleet's instance variable(s) unchanged.

Uses only language elements that we've covered so far, includes the sorting code.

The Previous Lab (for reference only)

Write a class Fleet. A Fleet object maintains a collection of Car objects. We will assume that all of the car identifiers in the fleet are unique. A Fleet keeps an

ArrayList as an instance varible

It has a no-argument constructor

accessors:

int size() // Returns the number of cars in the fleet

double getCarAverageMPG() // returns the average miles per gallon of all the cars in the fleet, or -1 if the fleet has no cars

double getFleetAverageMPG() // returns the miles per gallon of the fleet as a whole (i.e., uses the fleet's fuel consumption instead of number of cars), or -1 if the fleet has consumed no fuel

int getTotalMiles() // returns the total miles driven by the fleet

int getTotalFuel() // returns the total fuel consumed by the fleet

Car find(String carId) // returns the Car object with the given car identifier, or null if there is no such car

Car get(int position) // returns the Car in the given position in the fleet. Cars are maintained in insertion order, so the first car is in position 0, the second in position 1, etc.

String toString() // returns a String representation of the object, something like

Fleet [ 

Car [identifier=Ford1950, miles=160000, fuelUsed=16000] 

Car [identifier=Buick1964, miles=50000, fuelUsed=3500] 

] 

mutators:

boolean add(Car carToAdd) // adds the carToAdd to the fleet's collection of cars and returns true if the addition was successful, false otherwise

What I have so far...

Car.java

package fleetss;

public class Car { public String ident; public int totFuel; public int totMiles; public Car(){ ident = ""; totFuel = 0; totMiles = 0; } public Car(String identifier) { ident = identifier; totFuel = 0; totMiles = 0; } public Car(String identifier, int miles, int fuelUsed) { ident = identifier; totFuel = fuelUsed; totMiles = miles; } public String getIdentifier() { return ident; } public int getFuelUsed() { return totFuel; } public int getMiles() { return totMiles; } public double getMPG() { return totMiles * totFuel; } public int compareMPG(Car otherCar) { if (otherCar.getMPG() > this.getMPG()) { return -1; } else if (otherCar.getMPG() < this.getMPG()) { return 1; } else { return 0; } } public String toString() { return "Car [identifier="+getIdentifier()+", miles="+getMiles()+", fuelUsed="+getFuelUsed()+"]"; } public void setIdentifier(String identifier) { ident = identifier; } public void setFuelUsed(int fuelUsed) { totFuel = fuelUsed; } public void setMiles(int miles) { totMiles = miles; } public void addFuel(int fuelAmount) { totFuel += fuelAmount; } public void addMiles(int milesTraveled) { totMiles += milesTraveled; } }

Fleets.java

package fleetss;

import java.util.ArrayList;

public class Fleet { private ArrayList carList; public Fleet() { carList=new ArrayList(); } public int size() { return carList.size(); } public double getCarAverageMPG() { double sumMPG=0; if(carList.size()!=0) { for(Car c:carList) { sumMPG+=c.getMPG(); } return sumMPG/carList.size(); } return -1; } public double getFleetAverageMPG() { double sumMPG=0; double sumFule=0; if(carList.size()!=0) { for(Car c:carList) { sumMPG+=c.getMPG(); sumFule+=c.getFuelUsed(); } return sumMPG/sumFule; } return -1; } public int getTotalMiles() { int sum=0; for(Car c:carList) { sum+=c.getMiles(); } return sum; } public int getTotalFule() { int sum=0; for(Car c:carList) { sum+=c.getFuelUsed(); } return sum; } public Car find(String carId) { for(Car c:carList) { if(c.getIdentifier().equalsIgnoreCase(carId)) return c; } return null; } public Car get(int position) { return carList.get(position); } public String toString() { String string="Fleet["; for(Car c:carList) { string+=" Car[identifier="+c.getIdentifier()+", miles="+c.getMiles()+", fuleUsed="+c.getFuelUsed()+"]"; } string+=" ]"; return string; } public boolean add(Car carToAdd) { return carList.add(carToAdd); } }

FleetTester.java

package fleetss;

public class FleetTester { public static void main(String[] args) { Fleet fleet=new Fleet(); Car car; System.out.println("add: "+fleet.add(new Car("Ford1950",160000,16000))); System.out.println("add: "+fleet.add(new Car("Buick1964",50000,3500))); System.out.println("Size: "+fleet.size()); System.out.println("CarAvgMPG: "+fleet.getCarAverageMPG()); System.out.println("FleetAvgMPG: "+fleet.getFleetAverageMPG()); System.out.println("Total Miles: "+fleet.getTotalMiles()); System.out.println("Total Fule: "+fleet.getTotalFule()); System.out.println("Car Find: "+fleet.find("buick1964")); System.out.println("get(position): "+fleet.get(0)); System.out.println("To String: "+fleet.toString()); } }

FleetTestMain.java

import java.util.ArrayList;

// note: all the new String(new String("xyz")

// is to flush out anyone using == to compare String objects

// note: this code looks a bit odd because I derived it

// from a JUNIT test class

public class FleetTestMain {

// milage (l, m, h); fuel(l, m, h), mpg(l, m, h)

static final Car[] CAR_ARRAY = {

new Car(new String("lhl"), 100, 200), // 0

new Car(new String("lmm"), 100, 5), // 1

new Car(new String("llh"), 100, 2), // 2

new Car(new String("mhl"), 500, 200), // 3

new Car(new String("mmm"), 600, 5), // 4

new Car(new String("mlh"), 550, 2), // 5

new Car(new String("hhl"), 1001, 200), // 6

new Car(new String("hmm"), 1000, 5), // 7

new Car(new String("hlh"), 1000, 2), // 8

};

public static void main(String[] args) {

int failCount = 0;

if (!testFindById())

failCount++;

if (!testGetCarAverageMPG())

failCount++;

if (!testGetCarBestMPG())

failCount++;

if (!testGetCarHighestMilage())

failCount++;

if (!testGetFleetAverageMPG())

failCount++;

if (!testGetTotalFuel())

failCount++;

if (!testGetTotalMilage())

failCount++;

if (!testSortByMPG())

failCount++;

if (failCount == 0) {

System.out.println("Congrats, you made it");

} else {

System.out.println("There are " + failCount + " bugs remaining");

}

}

public static boolean testFindById() {

Fleet fl = new Fleet();

for (Car c : CAR_ARRAY) {

fl.add(c);

}

Car c = fl.findById(new String("mlh"));

if (!(CAR_ARRAY[5].equals(c))) {

System.out.println("findById failed, expected car " + CAR_ARRAY[5].toString() + " found " + c);

return false;

}

return true;

}

public static boolean testGetFleetAverageMPG() {

Fleet fl = new Fleet();

fl.add(CAR_ARRAY[3]);

fl.add(CAR_ARRAY[7]);

double mpg = fl.getFleetAverageMPG();

if (!(Math.abs(7.317 - mpg) < .001)) {

System.out.println("fleet mpg bad for " + CAR_ARRAY[3] +

" and " + CAR_ARRAY[7] + " expected 7.317, found " + mpg);

return false;

}

return true;

}

public static boolean testGetCarAverageMPG() {

Fleet fl = new Fleet();

fl.add(CAR_ARRAY[3]);

fl.add(CAR_ARRAY[7]);

double mpg = fl.getCarAverageMPG();

if (!(Math.abs(101.25 - mpg) < .001)) {

System.out.println("car avg mpg bad for " + CAR_ARRAY[3] + " and " + CAR_ARRAY[7]

+ " expected 101.25, but was " + mpg);

return false;

}

return true;

}

public static boolean testGetTotalFuel() {

Fleet fl = new Fleet();

fl.add(CAR_ARRAY[3]);

fl.add(CAR_ARRAY[7]);

int fuel = fl.getTotalFuel();

if (!(205 == fuel)) {

System.out.println("total fuel bad for " + CAR_ARRAY[3] + " and " + CAR_ARRAY[7]);

return false;

}

return true;

}

public static boolean testGetTotalMilage() {

Fleet fl = new Fleet();

fl.add(CAR_ARRAY[3]);

fl.add(CAR_ARRAY[7]);

int miles = fl.getTotalMiles();

if (!(1500 == miles)) {

System.out.println("total miles bad for " + CAR_ARRAY[3] + " and " + CAR_ARRAY[7]);

return false;

}

return true;

}

public static boolean testGetCarBestMPG() {

Fleet fl = new Fleet();

for (Car c : CAR_ARRAY) {

fl.add(c);

}

Car best = fl.getCarBestMPG();

if (!(best.getIdentifier().equals("hlh"))) {

System.out.println("best mpg bad, expected " + CAR_ARRAY[8] + " found " + best);

return false;

}

return true;

}

public static boolean testGetCarHighestMilage() {

Fleet fl = new Fleet();

for (Car c : CAR_ARRAY) {

fl.add(c);

}

Car best = fl.getCarHighestMilage();

if (!(best.getIdentifier().equals("hhl"))) {

System.out.println("highest milage bad expected " + CAR_ARRAY[6] + " found " + best);

return false;

}

return true;

}

public static boolean testSortByMPG() {

Fleet fl = new Fleet();

for (Car c : CAR_ARRAY) {

fl.add(c);

}

ArrayList sorted = fl.getSortedByMPG();

if (sorted.size() != CAR_ARRAY.length) {

System.out.println("sortedByMPG returned wrong number of elements, should be " + CAR_ARRAY.length

+ " but was " + sorted.size());

return false;

}

for (int i = 0; i < CAR_ARRAY.length - 2; i++) {

Car current = sorted.get(i);

Car next = sorted.get(i + 1);

if (!(current.getMPG() <= next.getMPG())) {

System.out.println("sorted arraylist is not in order: car( new String(" + i + ") is " + sorted.get(i)

+ " car( new String(" + (i + 1) + ") is " + sorted.get(i + 1));

return false;

}

}

boolean sameOrder = true;

int j = 0;

while (sameOrder && j < fl.size()) {

if (!(fl.get(j).getIdentifier().equals(sorted.get(j).getIdentifier())))

sameOrder = false;

j++;

}

if (sameOrder) {

System.out.println(

"fleet's internal array list was sorted instead of a copy being made of it and the copy sorted ");

return false;

}

return true;

}

}