Question

Java ArrayList Parking Ticket Simulator, Hello I am stuck on this problem where I am asked to calculate the sum of all fines in the policeOfficer class from the arraylist i created. I modified the issueParking ticket method which i bolded at the very end to add each issued Parking ticket to the arrayList, i think thats the right way? if not please let me know. What I dont understand how to do is access the fineAmountInCAD from the arrayList to sum it all up? Do i use a for loop? if so how do i just get the fineAmount and have it calculate the sum of that specific variable?

Parking Ticket Class

public class ParkingTicket {
   private String officerName;
   private String officerBadgeNumber;
   private String ticketNumber;
   private String carLicensePlateNumber;
   private double fineAmountInCAD;
        public static int counter = 1000;
   public static final String TICKET_PREFIX = "VAN";
  
  
   public ParkingTicket(String name, String badgeNumber, String carLicense, double fine) {
       generatTicketNumber();
       setOfficerName(name);
       setOfficerBadgeNumber(badgeNumber);
       setCarLicensePlateNumber(carLicense);
       setFineAmountInCAD(fine);
      
   }
  
  
   private void generatTicketNumber() {
       ticketNumber = TICKET_PREFIX + ++counter;
      
   }

   public String getOfficerName() {
       return officerName;
   }
   public void setOfficerName(String name) {
       if(name != null && name.length() > 0) {
       this.officerName = name;
       } else if (name == null) {
           throw new IllegalArgumentException("officer name must not be null");
       } else {
           throw new IllegalArgumentException ("officer name must not be an empty String");
       }
   }

   public String getOfficerBadgeNumber() {
       return officerBadgeNumber;
   }

   public void setOfficerBadgeNumber(String badgeNumber) {
       if(badgeNumber != null && badgeNumber.length() > 0) {
           officerBadgeNumber = badgeNumber;
       } else if (badgeNumber == null) {
           throw new IllegalArgumentException("badge number must not be null");
       } else {
           throw new IllegalArgumentException ("badge number must not be empty String");
       }
   }

   public String getCarLicensePlateNumber() {
       return carLicensePlateNumber;
   }

   public void setCarLicensePlateNumber(String licensePNumber) {
       if(licensePNumber != null && licensePNumber.length() > 0) {
           carLicensePlateNumber = licensePNumber;
       } else if (licensePNumber == null) {
           throw new IllegalArgumentException("car license plate number must not be null");
       } else {
           throw new IllegalArgumentException ("car license plate number must not be empty String");
       }
   }

   public double getFineAmountInCAD() {
       return fineAmountInCAD;
   }

   public void setFineAmountInCAD(double fine) {
       if(fine > 0) {
           fineAmountInCAD = fine;
       }else if(fine == 0) {
           throw new IllegalArgumentException("fine amount must not be 0");
       }else {
           throw new IllegalArgumentException("fine amount must not be negative");
       }
   }
  

   public String getTicketNumber() {
       return ticketNumber;
   }
  
   public void displayDetails() {
       System.out.println("Ticket Number: "+ ticketNumber);
       System.out.println("Officer Name: "+ officerName);
       System.out.println("Officer Badge number: " + officerBadgeNumber);
       System.out.println("Car License Plate Number: "+ carLicensePlateNumber);
       System.out.println("Fine amount: "+ fineAmountInCAD);
   }
  
   public static void main(String[] args) {
       ParkingTicket ticket = new ParkingTicket("Bob Smith", "RCMP2251", "1A2B3C", 150.0);
       ticket.displayDetails();
   }
  
   public static void resetCounter() {
       counter = 1000;
  
   }
}

Police Officer Class

import java.util.ArrayList;


public class PoliceOfficer
{
    public static final int ONE_HOUR_FINE_AMOUNT = 20;
    public static final int MINUTES_IN_HOUR = 60;

    private String officerName;
    private String officerBadgeNumber;
    private ArrayList<ParkingTicket> ticketList;

    public PoliceOfficer(String name, String badgeNumber){
     setOfficerName(name);
     setOfficerBadgeNumber(badgeNumber);
     ticketList = new ArrayList<ParkingTicket>();
    }

    public ArrayList<ParkingTicket> getTicketList(){
        return ticketList;
    }

    public String getOfficerName(){
        return officerName;
    }

    public String getOfficerBadgeNumber(){
        return officerBadgeNumber;
    }

    public void setOfficerName(String officerName){
        if(officerName !=null && !officerName.isEmpty()){
            this.officerName = officerName;
        } else if(officerName == null){
            throw new IllegalArgumentException("officer name must not be null");
        } else if(officerName.isEmpty()) {
            throw new IllegalArgumentException("officer name must not be an empty String");
  
    }
    }

    public void setOfficerBadgeNumber(String officerBadgeNumber){
        if(officerBadgeNumber !=null && !officerBadgeNumber.isEmpty()){
            this.officerBadgeNumber = officerBadgeNumber;
        } else if(officerBadgeNumber == null) {
            throw new IllegalArgumentException("badge number must not be null");
        } else if(officerBadgeNumber.isEmpty()){
            throw new IllegalArgumentException("badge number must not be empty String");
     
     }
   }

   private boolean isParkingTimeExpired(ParkedCar car, ParkingMeter meter){
        if(car.getNumberOfMinutesParked() > meter.getNumberOfPurchasedMinutes())
        {
            return true;
        } else{
            return false;
        }   
     }      

      private double calculateFine(ParkedCar car, ParkingMeter meter){
     
    int totalFine = 0;
    int minutes = car.getNumberOfMinutesParked() - meter.getNumberOfPurchasedMinutes();
     if(isParkingTimeExpired(car,meter)){
      if(minutes % 60 == 0)
      totalFine = (minutes/60) * ONE_HOUR_FINE_AMOUNT;
       else
     totalFine = ((minutes/60) + 1) * ONE_HOUR_FINE_AMOUNT;
     }
     return totalFine;
    }
  

    public void issueParkingTicket(ParkedCar car,ParkingMeter meter){
      
        if(isParkingTimeExpired(car,meter) == true){
          ParkingTicket ticket = new ParkingTicket(officerName,officerBadgeNumber,car.getLicensePlateNumber(),calculateFine(car,meter));
          ticket.displayDetails();
          ticketList.add(ticket);
    
    }

    }
  
    public double sumAllFines(ArrayList<ParkingTicket> tickets){
     
    }
  
}      

   public ParkingTicket issueParkingTicket(ParkedCar car,ParkingMeter meter){
      
        if(isParkingTimeExpired(car,meter) == true){
          ParkingTicket ticket = new ParkingTicket(officerName,officerBadgeNumber,car.getLicensePlateNumber(),calculateFine(car,meter));
          ticket.displayDetails();
        
       
          return ticket;
            } else
             { return null;
    }         
   }

Answer 1

Question:  I modified the issueParking ticket method which i bolded at the very end to add each issued Parking ticket to the arrayList, i think thats the right way?

Answer:

• That's correct way of doing. I noticed that you have two methods with the same name "issueParkingTickets" with the same parameters. Hence, commented out one method.

Question: What I dont understand how to do is access the fineAmountInCAD from the arrayList to sum it all up? Do i use a for loop? if so how do i just get the fineAmount and have it calculate the sum of that specific variable?

Answer:

• Yes, use for loop to iterate through all the tickets in the list and get the fine amount using getter method "getFineAmountInCAD()".
• And you no need to pass the arraylist to the method sumAllFines as the tickets arraylist is already member of the class and can be accessed inside the function.

Since there were no information about classes ParkedCar and ParkingMeter and how to test the methods, I could not give you test driver class.

All other classes and methods remain same. Just modified sumAllFines method in PoliceOfficer.java File.

import java.util.ArrayList;

public class PoliceOfficer

{

    public static final int ONE_HOUR_FINE_AMOUNT = 20;

    public static final int MINUTES_IN_HOUR = 60;

    private String officerName;

    private String officerBadgeNumber;

    private ArrayList<ParkingTicket> ticketList;

    public PoliceOfficer(String name, String badgeNumber){

        setOfficerName(name);

        setOfficerBadgeNumber(badgeNumber);

        ticketList = new ArrayList<ParkingTicket>();

    }

    public ArrayList<ParkingTicket> getTicketList(){

        return ticketList;

    }

    public String getOfficerName(){

        return officerName;

    }

    public String getOfficerBadgeNumber(){

        return officerBadgeNumber;

    }

    public void setOfficerName(String officerName){

        if(officerName !=null && !officerName.isEmpty()){

            this.officerName = officerName;

        } else if(officerName == null){

            throw new IllegalArgumentException("officer name must not be null");

        } else if(officerName.isEmpty()) {

            throw new IllegalArgumentException("officer name must not be an empty String");

        }

    }

    public void setOfficerBadgeNumber(String officerBadgeNumber){

        if(officerBadgeNumber !=null && !officerBadgeNumber.isEmpty()){

            this.officerBadgeNumber = officerBadgeNumber;

        } else if(officerBadgeNumber == null) {

            throw new IllegalArgumentException("badge number must not be null");

        } else if(officerBadgeNumber.isEmpty()){

            throw new IllegalArgumentException("badge number must not be empty String");

        }

   }

   private boolean isParkingTimeExpired(ParkedCar car, ParkingMeter meter){

        if(car.getNumberOfMinutesParked() > meter.getNumberOfPurchasedMinutes())

        {

            return true;

        } else{

            return false;

        }  

     }     

    private double calculateFine(ParkedCar car, ParkingMeter meter){

        int totalFine = 0;

        int minutes = car.getNumberOfMinutesParked() - meter.getNumberOfPurchasedMinutes();

        if(isParkingTimeExpired(car,meter)){

            if(minutes % 60 == 0)

              totalFine = (minutes/60) * ONE_HOUR_FINE_AMOUNT;

            else

             totalFine = ((minutes/60) + 1) * ONE_HOUR_FINE_AMOUNT;

        }

        return totalFine;

    }

    public void issueParkingTicket(ParkedCar car, ParkingMeter meter){

        if(isParkingTimeExpired(car, meter) == true){

          ParkingTicket ticket = new ParkingTicket(officerName, officerBadgeNumber, car.getLicensePlateNumber(), calculateFine(car, meter));

          ticket.displayDetails();

          ticketList.add(ticket);

        }

    }

    

    /*public ParkingTicket issueParkingTicket(ParkedCar car, ParkingMeter meter){  

        if(isParkingTimeExpired(car,meter) == true){

          ParkingTicket ticket = new ParkingTicket(officerName, officerBadgeNumber, car.getLicensePlateNumber(),c alculateFine(car,meter));

          ticket.displayDetails();

          return ticket;

        } else {

            return null;

        }

    } */  

    

    public double sumAllFines(){

        double totalfine = 0;

        //Loop through all the tickets and add the fine amount to total

        for(ParkingTicket ticket : ticketList){

            totalfine += ticket.getFineAmountInCAD();

        }

        return totalfine;

    }

}

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Happy Studying!!!

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