Question

IN JAVA 1.Write a class Item with these following requirements

ØHas two properties: itemName (text) and MSRP (decimal)

ØHas a getTax() method that has no implementation. This method returns a decimal value

ØHas a finalPrice() method that returns the price after tax

ØThis class cannot be instantiated

ØThis class is encapsulated

2.Write a class Electronics that inherits Item with these following requirements

ØHas two properties: manufacturer (text) and tax (decimal). tax value is shared among all electronic items

ØHas a constructor that initializes all attributes

ØProvide an implementation for getTax()

ØThis class is encapsulated

3.Write a class Shop that sells electronic items with these following requirements

ØHas two properties: shopName (text) and itemSold (collection). itemSold stores all the items that the shop sold. You can choose any Java built-in collection type that you like

ØHas a constructor (you can decide which input to have)

ØHas a method sellItem() that add a sold item to itemSold

ØHas a method getSoldList() that returns the names of all items sold in an array. This method shows an error when the collection is empty

ØThis class is encapsulated

4.Write a class Test that creates a Shop, sells a few items, then test getSoldList() and sortSoldList()

ØAssuming tax rate is 7%

Answer 1

Item.java

// abstract class Item ( can not instantiate abstract class)
public abstract class Item {
   // instance variables
   private String itemName;
   private double MSRP;
   // default constructor
   public Item() {
       super();
   }
   // parameterized constructor
   public Item(String itemName, double mSRP) {
       super();
       this.itemName = itemName;
       MSRP = mSRP;
   }
   // abstract method
   public abstract double getTax();
   // method to calculate and return final price of item
   public double finalPrice() {
       return MSRP+this.getTax();
   }
   // setter and getter methods
   public String getItemName() {
       return itemName;
   }
   public void setItemName(String itemName) {
       this.itemName = itemName;
   }
   public double getMSRP() {
       return MSRP;
   }
   public void setMSRP(double mSRP) {
       MSRP = mSRP;
   }
  
}

Electronics.java

public class Electronics extends Item {
   // instance variable
   private String manufacturer;
   private static double tax;
   // default constructor
   public Electronics() {
       super();
       tax=7;
   }
   // parameterized constructor
   public Electronics(String itemName, double mSRP, String manufacturer) {
       super(itemName, mSRP); // calling super class constructor
       this.manufacturer = manufacturer;
       tax=7; // tax rate 7%
   }

   @Override
   public double getTax() {
       return getMSRP()*tax/100;
   }
   // setter and getter
   public String getManufacturer() {
       return manufacturer;
   }
   public void setManufacturer(String manufacturer) {
       this.manufacturer = manufacturer;
   }
}

Shop.java

import java.util.ArrayList;
import java.util.List;

public class Shop {
   // instance varibales
   private String shopName;
   private List<Item> itemSold;
   // parameterized constructor
   public Shop(String shopName) {
       super();
       this.shopName = shopName;
       this.itemSold = new ArrayList<Item>(); // Items List
   }
   // method to add sold item to sold items list
   public void sellItem(Item item) {
       itemSold.add(item);
   }
   // method to return sold items list
   public List<Item> getSoldList() {
       return itemSold;
   }
}

Test.java

import java.util.List;

public class Test {
   public static void main(String[] args) {
       // Shop object
       Shop shop=new Shop("Electronics Store");
       // creating Item objects
       Item mouse=new Electronics("Mouse", 120.5, "HP");
       Item hardDisk=new Electronics("Hard Disk", 428.0, "Toshiba");
       Item monitor=new Electronics("Monitor", 520.0, "Intel");
       Item keyboard=new Electronics("Keyboard", 120.5, "Dell");
       Item laptop=new Electronics("Laptop", 1200.0, "Apple");
       // sell some items
       shop.sellItem(laptop);
       shop.sellItem(hardDisk);
       shop.sellItem(keyboard);
       // get all sold items list
       List<Item> soldItemList=shop.getSoldList();
       // print all sold items list with selling price including tax
       for (Item item : soldItemList) {
           System.out.println(item.getItemName()+" sold for $"+item.finalPrice());
       }
   }
}

Sample output: