Question

(JAVA) Create three classes, Vehicle, Truck, and Person. The Vehicle class has a make and model, test emissions per mile, and a driver/owner (= Person object). (Each vehicle can only have one driver/owner.) The class Truck is a derived class from the Vehicle class and has additional properties load capacity in tons (type double since it can contain a fractional part) and a towing capacity in pounds (type int). Be sure that your classes have appropriate constructors, accessors, mutators, equals(), and toString() methods.

The equals()and toString() methods should each include an @Override annotation.

Suppose each vehicle can keep track of emissions over time. Suppose also that after three months, the number of miles and emissions (in grams) are reported. At this point, if the vehicle’s emissions per mile exceed .2 grams per mile, the vehicle will be recalled. If the vehicle is a truck, emissions per mile may not exceed .4 grams per mile. If recalled, the vehicles are no longer street legal.

Your Person class should keep track of whether a driver has a license or has lost their license. You may assume that all people start with a license.

OUTPUT:

Person 1: Tom Night has a driver's license.

Person 2: Maya Light has a driver's license.

Person 3: Scott Troy has a driver's license.

The Toyota Camry, owned by Tom, is not street legal, with emissions per mile of 0.32.


The Toyota Camry, owned by Maya, is not street legal, with emissions per mile of 0.31.

The Honda Accord, owned by Scott, is street legal, with emissions per mile of 0.25.

Scott Troy has a driver's license

Answer 1

Program Code [JAVA]

// Person class

import java.util.Objects;

class Person {

    // Required instance variables

    private String firstName;
    private String lastName;
    private boolean hasLicense;

    // Constructor

    public Person(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;

        // Initially, person has driver's license
        this.hasLicense = true;
    }

    // Setters and Getters

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public boolean isHasLicense() {
        return hasLicense;
    }

    public void setHasLicense(boolean hasLicense) {
        this.hasLicense = hasLicense;
    }

    // toString and equal methods

    @Override
    public String toString() {
        if(hasLicense)
            return firstName + " " + lastName + " has a driver's license.";
        else
            return firstName + " " + lastName + " has not a driver's license.";
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof Person)) return false;
        Person person = (Person) o;
        return isHasLicense() == person.isHasLicense() &&
                Objects.equals(getFirstName(), person.getFirstName()) &&
                Objects.equals(getLastName(), person.getLastName());
    }
}

// Vehicle class

class Vehicle {

    private String make;
    private String model;
    private double emissionPerMile;
    private Person driver;

    // constructor & setters & getters

    public Vehicle(String make, String model, double emissionPerMile, Person driver) {
        this.make = make;
        this.model = model;
        this.emissionPerMile = emissionPerMile;
        this.driver = driver;
    }

    public String getMake() {
        return make;
    }

    public void setMake(String make) {
        this.make = make;
    }

    public String getModel() {
        return model;
    }

    public void setModel(String model) {
        this.model = model;
    }

    public double getEmissionPerMile() {
        return emissionPerMile;
    }

    public void setEmissionPerMile(double emissionPerMile) {
        this.emissionPerMile = emissionPerMile;
    }

    public Person getDriver() {
        return driver;
    }

    public void setDriver(Person driver) {
        this.driver = driver;
    }

    // An additional method which determines whether this vehicle is street legal or not

    public String getStreetLegal() {

        if (emissionPerMile > .2)
            return "not street legal";
        else
            return "street legal";
    }

    // toString which prints all details as shown in same output

    @Override
    public String toString() {
        return "The " + make + " " + model + ", owned by " + driver.getFirstName()
                + ", is " + getStreetLegal() + ", with emission per mile of " + emissionPerMile + ".";
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof Vehicle)) return false;
        Vehicle vehicle = (Vehicle) o;
        return Double.compare(vehicle.getEmissionPerMile(), getEmissionPerMile()) == 0 &&
                Objects.equals(getMake(), vehicle.getMake()) &&
                Objects.equals(getModel(), vehicle.getModel()) &&
                Objects.equals(getDriver(), vehicle.getDriver());
    }
}

// Truck class

class Truck extends Vehicle {

    private double loadCapacity;
    private int towingCapacity;

    public Truck(String make, String model, double emissionPerMile, Person driver, double loadCapacity, int towingCapacity) {
        super(make, model, emissionPerMile, driver);
        this.loadCapacity = loadCapacity;
        this.towingCapacity = towingCapacity;
    }

    // Accessor & Mutators(Getters & Setter)

    public double getLoadCapacity() {
        return loadCapacity;
    }

    public void setLoadCapacity(double loadCapacity) {
        this.loadCapacity = loadCapacity;
    }

    public int getTowingCapacity() {
        return towingCapacity;
    }

    public void setTowingCapacity(int towingCapacity) {
        this.towingCapacity = towingCapacity;
    }

    // Re-implementing getStreetLegal method for Truck class

    @Override
    public String getStreetLegal() {

        if (getEmissionPerMile() > .4)
            return "not street legal";
        else
            return "street legal";
    }


    // toString & equals method

    @Override
    public String toString() {

        return "The truck " + getMake() + " " + getModel() + ", owned by " + getDriver().getFirstName()
                + ", is " + getStreetLegal() + ", with load capacity of " + loadCapacity
                +", and towing capacity of " + towingCapacity + " anbd with emission per mile of " + getEmissionPerMile() + ".";
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof Truck)) return false;
        if (!super.equals(o)) return false;
        Truck truck = (Truck) o;
        return Double.compare(truck.loadCapacity, loadCapacity) == 0 &&
                towingCapacity == truck.towingCapacity;
    }
}

// A test class to test classes & generate required output as in question

public class Test {

    public static void main(String[] args) {

        Person person1 = new Person("Tom", "Night");
        Person person2 = new Person("Maya", "Light");
        Person person3 = new Person("Scott", "Troy");

        // Printing them

        System.out.println("Person 1: " + person1);
        System.out.println("Person 2: " + person2);
        System.out.println("Person 3: " + person3);

        // Now creating three vehicles

        Vehicle vehicle1 = new Vehicle("Toyota", "Camry", 0.32, person1);
        Vehicle vehicle2 = new Vehicle("Toyota", "Camery", 0.31, person2);
        Vehicle vehicle3 = new Vehicle("Honda", "Accord", 0.2, person3);

        System.out.println(vehicle1);
        System.out.println(vehicle2);
        System.out.println(vehicle3);

        System.out.println(person3);
    }
}

Sample Output:-

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