Question

Demonstrate the following:

1. Usage of Eclipse
2. Variable Assignment
3. Looping (for, while etc)
4. ArrayList (using object)
5. Object based programming
6. User Interaction with multiple options
7. Implementing Methods in relevant classes

Instructions

• Start with below java files:
• Item.java

  • Pages

    //add package statement here

    public class Item {

    private int id;

    private double price;

    public Item(int id, double price){

    this.id = id;

    this.price = price;

    }

    public int getId() {

    return id;

    }

    public void setId(int id) {

    this.id = id;

    }

    public double getPrice() {

    return price;

    }

    public void setPrice(double price) {

    this.price = price;

    }

    public String toString(){

    String item_desc = "Item Id: " + String.valueOf(id) + ", Cost: $";

    //modify item_desc to contain item description in the following format-

    Item Id: 123, Cost: $20.50 added in ShoppingCart with Quantity 20

    return item_desc;

    }

    }

• ShoppingCart.java

  • /**

    Order class maintains the Items that are part of the order.

    */

    //add package staement here

    import java.util.ArrayList;

    public class ShoppingCart

    {

    public static final double LOW_DISCOUNT = 0.10;

    public static final double MEDIUM_DISCOUNT = 0.25;

    public static final double HIGH_DISCOUNT = 0.50;

    ArrayList<Item> itemArray = new ArrayList<Item>();

    private String customerName;

    public String getCustomerName() {

    return customerName;

    }

    public void setCustomerName(String customerName) {

    this.customerName = customerName;

    }

    public ShoppingCart(String customerName){

    //implement here

    }

    public void addItemToCart(Item item, int quanity) {

    //If item already exists then update the quantity of that item by

    calling updateItemQuantity

    //If a new item is added, add the item to itemArray and fetch the

    details of the item added by calling toString() in Item;

    //print the fetched string here

    //donot display the details here if the item is updated, that should be

    done inside updateItemQuantity()

    }

    public void addItemToCart(int itemId, double itemPrice, int itemQuantity) {

    //Create Object of Item

    //Call addItemToCart(Item item, int quanity)

    }

    public void updateItemQuantity(int itemID, int newQuantity)

    {

    //implement code to change the quantity of an item

    String item_updated = "Quantity for Item Id: " + String.valueOf(itemID)

    + ", Cost: $";

    //modify item_updated to display data in the following format-

    'Quantity for Item Id: 123, Cost: $20.50 is changed to 25'

    //print item_updated

    }

    public void removeItemFromCart(int itemID)

    {

    //implement here

    }

    }

    public double calculateItemBasedDiscount()

    {

    double discount = 0;

    //If total number of quantity ACROSS ALL Items is less than 11 , apply

    LOW_DISCOUNT (10% discount)

    //If total number of quantity ACROSS ALL Items is more than 10 but less

    than 26, apply MEDIUM_DISCOUNT (25% discount)

    //If total number of quantity ACROSS ALL Items is more than 26, apply

    HIGH_DISCOUNT (50% discount)

    return discount;

    }

    /**

    *

    * @return

    */

    public double getTotalCost() {

    double totalFinalCost = 0;

    //Compute the cost by adding cost of each item. Make sure to multiply

    quantity and price per unit for cost of each item.

    //Find applicable discount using calculateItemBasedDiscount and apply

    the discount to find the final cost

    return totalFinalCost;

    }

    }

• ShoppingCartTester.java

  • //add package statement here

    public class ShoppingCartTester {

    public static void main(String[] args) {

    //Add code here to display main menu along with all the options

    //Keep on looping until the user enters 6 to exit. DO NOT EXIT

    otherwise

    //If any number other than 1-6 is entered, display an error message

    "Enter input in the range 1-6"; and again ask for input

    //Demo code

    /*

    ShoppingCart shoppingCart= new ShoppingCart();

    System.out.println("Add Item Id: 1");

    System.out.println("Add Item Cost per unit: 1.5");

    int id = 1;

    double costPerUnit = 1.5;

    int quantity = 10;

    Item item = new Item(id, costPerUnit);

    shoppingCart.addItemToCart(item, quantity);

    userInputSimulator();

    */

    }

    public static void userInputSimulator()

    {

    //Use Scanner to get input for item quantity and item cost

    ShoppingCart shoppingCart = new ShoppingCart();

    shoppingCart.addItemToCart(item, quanity);();

    //System.out.print("Discount Code should be 0.5 : " + discountLevel);

    double finalCost = order.getTotalCost();

    //System.out.print("FInal cost should be : " + finalCost);

    //Additional testing

    //Add sensible function calls to test functionality of ALL methods in

    ShoppingCart.java

    //Display the final cost

    }

    }

    /* Note:

    Meticulously read the instructions explaining how marks will be awarded for this

    assignment.

    Perform error handling. Eg: donot accept values outside the range(1-6) donot accept

    negative values for QUANTITY or PRICE of an ITEM

    */

• You will model ShoppingCart as java Class.
• ShoppingCart class will store Items in the cart. Item will be another java class. Item is identified by Id attribute. If the Item with the same Id is added multiple times in the cart, change the quantity and DO NOT add multiple Item objects with same Id.
• The program should prompt various actions on ShoppingCart
  • addItemToCart – Two overloads
  • updateItemQuantity
  • removeItemFromCart
  • calculateItemBasedDiscount
  • getTotalCost
• Based on the selected action ask for further input.
  For example, if user selects to “addItemToCart”, prompt user to enter
  • itemId
  • itemName
  • itemPrice
  • itemQuantity
• Implement all methods in ShoppingCart.java
• Write test in ShoppingCartTester.java. Use scanner to implement userInputSimulator() method. See sample output for sample run.
• Before you start working on user input, implement the tester methods as provided in the starter code. Once you have everything working enable the user input and comment out the tester code.
• Gracefully exit the program

Sample Output

WELCOME TO SHOPPING CART APPLICATION.

PLEASE ENTER YOUR NAME:

Joe Peters

Welcome Joe Peters. Your Shopping Cart is created.

-----------------------------------------------------------------------------

Select one of the following options:

1. Add Item in ShoppingCart
2. Update Quantity for Item in ShoppingCart
3. Remove Item from Shopping Cart
4. Calculate Item Based Discount
5. Get total cost
6. Exit

1

You have selected to Add Item in Shopping Cart

Please Enter Item Id:

123

Please Enter Item Price:

20.50

Please Enter Item Quantity:

20

Item "Id: 123, Cost: $20.50" is added in ShoppingCart with Quantity 20

Select one of the following options:

1. Add Item in ShoppingCart
2. Update Quantity for Item in ShoppingCart
3. Remove Item from Shopping Cart
4. Calculate Item Based Discount
5. Get total cost
6. Exit

2

You have selected to update Quantity for Item in ShoppingCart

Please Enter Item Id for which you want to change Quantity:

123

Please Enter new Quantity:

25

Quantity for Item "Id: 123, Cost: $20.50" is changed to 25

Select one of the following options:

1. Add Item in ShoppingCart
2. Update Quantity for Item in ShoppingCart
3. Remove Item from Shopping Cart
4. Calculate Item Based Discount
5. Get total cost
6. Exit

6

Are you sure you want to Exit(y/n)?

y

Good Bye Have a Nice Day!

Answer 1

// Item.java

public class Item {

   private int id;

   private double price;

   private int itemQuantity;

   public Item(int id, double price, int qty) {

       this.id = id;

       this.price = price;
       this.itemQuantity = qty;

   }

   public int getItemQuantity() {
       return itemQuantity;
   }

   public void setItemQuantity(int itemQuantity) {
       this.itemQuantity = itemQuantity;
   }

   public int getId() {

       return id;

   }

   public void setId(int id) {

       this.id = id;

   }

   public double getPrice() {

       return price;

   }

   public void setPrice(double price) {

       this.price = price;

   }

   public String toString() {

       String item_desc = "Item Id: " + String.valueOf(id) + ", Cost: $"
               + price + " added in ShoppingCart with Quantity "
               + itemQuantity;

       // modify item_desc to contain item description in the following format-

       // Item Id: 123, Cost: $20.50 added in ShoppingCart with Quantity 20

       return item_desc;

   }
}

_________________________

// ShoppingCart.java

/**

Order class maintains the Items that are part of the order.

*/

//add package staement here

import java.util.ArrayList;

public class ShoppingCart

{

   public static final double LOW_DISCOUNT = 0.10;

   public static final double MEDIUM_DISCOUNT = 0.25;

   public static final double HIGH_DISCOUNT = 0.50;

   ArrayList<Item> itemArray = new ArrayList<Item>();

   private String customerName;

   public String getCustomerName() {

       return customerName;

   }

   public void setCustomerName(String customerName) {

       this.customerName = customerName;

   }

   public ShoppingCart(String customerName) {

       // implement here
       setCustomerName(customerName);

   }

   public void addItemToCart(Item item, int quanity) {
       int flag = 0;
       // If item already exists then update the quantity of that item by
       // calling updateItemQuantity

       // If a new item is added, add the item to itemArray and fetch the
       // details of the item added by calling toString() in Item;

       // print the fetched string here

       // do not display the details here if the item is updated, that should
       // be done inside updateItemQuantity()
       for (int i = 0; i < itemArray.size(); i++) {
           if (itemArray.get(i).getId() == item.getId()) {
               flag = 1;
               break;
           }
       }
       if (flag == 1) {
           updateItemQuantity(item.getId(), quanity);
       } else {
           addItemToCart(item.getId(), item.getPrice(), item.getItemQuantity());
           System.out.println(item);
       }
   }

   public void addItemToCart(int itemId, double itemPrice, int itemQuantity) {

       // Create Object of Item
       Item i = new Item(itemId, itemPrice, itemQuantity);
       // Call addItemToCart(Item item, int quanity)

   }

   public void updateItemQuantity(int itemID, int newQuantity)

   {

       int indx = 0;
       // implement code to change the quantity of an item
       for (int i = 0; i < itemArray.size(); i++) {
           if (itemArray.get(i).getId() == itemID) {
               indx = i;
               break;
           }
       }

       String item_updated = "Quantity for Item Id: "
               + String.valueOf(itemArray.get(indx).getId())

               + ", Cost: $" + itemArray.get(indx).getPrice();

       itemArray.get(indx).setItemQuantity(newQuantity);

       // modify item_updated to display data in the following format-

       item_updated += " is changed to " + itemArray.get(indx).getPrice();

       // print item_updated
       System.out.println(item_updated);

   }

   public void removeItemFromCart(int itemID) {
       int indx = 0;
       // implement code to change the quantity of an item
       for (int i = 0; i < itemArray.size(); i++) {
           if (itemArray.get(i).getId() == itemID) {
               indx = i;
               break;
           }
       }
       itemArray.remove(indx);

   }

   public double calculateItemBasedDiscount()

   {

       double discount = 0;
       int totQty = 0;
       // If total number of quantity ACROSS ALL Items is less than 11 , apply
       // LOW_DISCOUNT (10% discount)

       // If total number of quantity ACROSS ALL Items is more than 10 but less
       // than 26, apply MEDIUM_DISCOUNT (25% discount)

       // If total number of quantity ACROSS ALL Items is more than 26, apply
       // HIGH_DISCOUNT (50% discount)
       for (int i = 0; i < itemArray.size(); i++) {
           totQty += itemArray.get(i).getItemQuantity();
       }

       if (totQty < 11) {
           discount = 10;
       } else if (totQty > 10 && totQty <= 26) {
           discount = 26;
       } else if (totQty > 26) {
           discount = 50;
       }
       return discount;

   }

   /**
   *
   *
   *
   * @return
   */

   public double getTotalCost() {

       double totalFinalCost = 0;

       // Compute the cost by adding cost of each item. Make sure to multiply
       // quantity and price per unit for cost of each item.
       for (int i = 0; i < itemArray.size(); i++) {
           totalFinalCost += itemArray.get(i).getPrice()
                   * itemArray.get(i).getItemQuantity();
       }
       // Find applicable discount using calculateItemBasedDiscount and apply
       // the discount to find the final cost
       totalFinalCost = totalFinalCost + (calculateItemBasedDiscount() / 100)
               * totalFinalCost;

       return totalFinalCost;

   }

}

___________________________

// ShoppingCartTester.java

import java.util.Scanner;

public class ShoppingCartTester {

   public static void main(String[] args) {

       String customerName;
       /*
       * Creating an Scanner class object which is used to get the inputs
       * entered by the user
       */
       Scanner sc = new Scanner(System.in);

       // Getting the input entered by the user
       System.out.println("WELCOME TO SHOPPING CART APPLICATION.");
       System.out.print("PLEASE ENTER YOUR NAME:");
       customerName = sc.nextLine();
       ShoppingCart shopcart = new ShoppingCart(customerName);
       System.out.println("Welcome " + shopcart.getCustomerName()
               + ". Your Shopping Cart is created.");
       // Add code here to display main menu along with all the options

       // Keep on looping until the user enters 6 to exit. DO NOT EXIT
       // otherwise

       // If any number other than 1-6 is entered, display an error message

       // "Enter input in the range 1-6"; and again ask for input

       // Demo code
       char yesorno;
while(true)
{
   while (true) {
            System.out.println("Select one of the following options:");

            System.out.println("1 - Add Item in ShoppingCart");
            System.out.println("2 - Update Quantity for Item in ShoppingCart");
            System.out.println("3 - Remove Item from Shopping Cart");
            System.out.println("4 - Calculate Item Based Discount");
            System.out.println("5 - Get total cost");
            System.out.println("6 - Exit");

            int choice = sc.nextInt();
            switch (choice) {
            case 1: {
                int id,qty;
                double price;
                System.out.println("You have selected to Add Item in Shopping Cart");
                System.out.print("Please Enter Item Id:");
                id=sc.nextInt();
                System.out.print("Please Enter Item Price:");
                price=sc.nextDouble();
                System.out.print("Please Enter Item Quantity:");
                qty=sc.nextInt();
               
                shopcart.addItemToCart(id,price,qty);
                continue;
            }
            case 2: {
                System.out.println("You have selected to update Quantity for Item in ShoppingCart");
                System.out.print("Please Enter Item Id for which you want to change Quantity:");
int id=sc.nextInt();
System.out.println("Please Enter new Quantity:");
int qty=sc.nextInt();
shopcart.updateItemQuantity(id,qty);

                continue;
            }
            case 3: {
                System.out.println("You have selected to Remove Item in ShoppingCart");
                System.out.print("Please Enter Item Id for which you want to remove:");
int id=sc.nextInt();
shopcart.removeItemFromCart(id);

                continue;
            }
            case 4: {
                System.out.println("You have selected to Display ItemBasedDiscount in ShoppingCart");
                System.out.print("Discount :%"+shopcart.calculateItemBasedDiscount());
  
                continue;
            }
            case 5: {
               
        System.out.print("Total Cost :$"+shopcart.getTotalCost());
  
                continue;
            }
            case 6: {
                break;
            }
            default: {
                System.out.println("** Invalid Choice **");
                continue;
            }

            }
            break;
        }

     
   System.out.print("Are you sure you want to Exit(y/n)?");
   yesorno=sc.next(".").charAt(0);
   if(yesorno=='y' || yesorno=='Y')
   {
       break;
   }

}
System.out.println("Good Bye Have a Nice Day!");
      
   }

}

________________________________Thank You