In Java, make abstract and concrete classes that complete a simple inventory system for a grocery store. You are going to create an abstract class called Food, and then three concrete subclasses called Fruit, Carbohydrate, and MeatFish. Fruit encompasses any kind of fruit, Carbohydrate encompasses breads and grains, and MeatFish encompasses meat and fish. You will see how easy such a situation is once you take advantage of polymorphism with an abstract class.

The GroceryInventory class creates an array of Food items. It adds to this array a series of concrete Food objects, such as apples, oranges, chicken, and rice. See the provided code. Each of the concrete objects represents a type of food and the quantity of it that the store has. As a user, you can enter item names followed by the quantity to purchase, such as Rice 50, which removes 50 units of rice from the store inventory. When you are done removing items (it is in a loop so you can test multiple items easily), type STOP to quit the loop. Finally, it will print the details of your purchase. The values for fat, protein, and sugar are in terms of calories for the entire purchase. It then outputs the updated inventory. Sample output is at the end of this document.

Class Food:

The Food class has a String for name, a String for the unit type, a double for the price per unit, a double for the amount of stock (which is in terms of the unit type defined), and the number of calories per unit. Food has a single constructor, which takes the name, unit, price, stock amount, and calories per unit, and sets all of the values of the current object accordingly.

Food has getters for fat (in percentage of calories), sugar (in percentage of calories), protein (in percentage of calories), name, price, and calories per unit, and they are called getFat(), getSugar(), getProtein(), getName(), getPrice(), and getCaloriesPerUnit() respectively. Food also has a method called decreaseStock which takes the amount of stock (in the units of the food item) to remove from the inventory. If there is enough stock to remove, remove the required amount and return true. Otherwise, return false and do not remove any stock. Finally, Food has an override for toString which prints the name of the food item, followed by , , followed by the price per unit in the format of $ followed by the price followed by / followed by the unit, which is followed by , and the amount of stock remaining, followed by and the unit for this food item, followed by in stock..

Class Carbohydrate:

Has a constructor, accepting name, unit, price, amount of stock, and calories per unit. The toString method should show Carbohydrate: followed by the toString() of Food. Carbohydrates have 20% calories from fat, 60% calories from sugar, and 20% calories from protein.

Class Fruit:

Constructor is the same as Carbohydrate. The toString method should show Fruit: followed by the toString() of Food. Fruits have 100% calories from sugar, 0% calories from fat, and 0% calories from protein.

Class MeatFish:

Same constructor as Carbohydrate and Fruit. The toString method should show MeatFish: followed by the toString() of Food. MeatFish have 70% calories from fat, 10% calories from sugar, and 20% calories from protein.

Sample Output:

Inventory:

Fruit: Apple, $1.89/kg, 200.35 kg in stock

Fruit: Orange, $2.36/dozen, 38.0 dozen in stock

Carbohydrate: Rice, $2.99/kg, 20.0 kg in stock

MeatFish: Chicken, $5.49/kg, 538.32 kg in stock

MeatFish: Lamb, $4.32/kg, 134.62 kg in stock

MeatFish: Shrimp, $9.65/kg, 74.52 kg in stock

Enter to buy

Type STOP to finish

Rice 2

Orange 3

Apple 1

Lamb 0

Shrimp 2

STOP

Total price: $34.25

Total calories from fat: 1440.0 calories

Total calories from sugar: 1820.0 calories

Total calories from protein: 540.0 calories

Inventory:

Fruit: Apple, $1.89/kg, 199.35 kg in stock

Fruit: Orange, $2.36/dozen, 35.0 dozen in stock

Carbohydrate: Rice, $2.99/kg, 18.0 kg in stock

MeatFish: Chicken, $5.49/kg, 538.32 kg in stock

MeatFish: Lamb, $4.32/kg, 134.62 kg in stock

MeatFish: Shrimp, $9.65/kg, 72.52 kg in stock

Class GroceryInventory:

import java.util.Scanner;

import java.util.StringTokenizer;

public class GroceryInventory {

public static final int maxFoodItems = 10;

private Food[] foodItems = new Food[maxFoodItems]; // Keep track of the store's inventory

private int totalFoodItems = 0;

public static void main(String[] args) {

// For input

Scanner keyboard = new Scanner(System.in);

String input;

StringTokenizer inputTokenizer;

// Stock up on items

GroceryInventory inventory = new GroceryInventory();

/************************************* Name unit price stock caloriesPerUnit**/

inventory.addFoodItem(new Fruit( "Apple", "kg", 1.89, 200.35, 200));

inventory.addFoodItem(new Fruit( "Orange", "dozen", 2.36, 38, 300));

inventory.addFoodItem(new Carbohydrate("Rice", "kg", 2.99, 20, 450));

inventory.addFoodItem(new MeatFish( "Chicken", "kg", 5.49, 538.32, 800));

inventory.addFoodItem(new MeatFish( "Lamb", "kg", 4.32, 134.62, 1200));

inventory.addFoodItem(new MeatFish( "Shrimp", "kg", 9.65, 74.52, 900));

System.out.println("Inventory:");

System.out.println("");

inventory.printInventory();

System.out.println("");

System.out.println("Enter to buy");

System.out.println("Type STOP to finish");

System.out.println("");

double totalPrice = 0;

double totalFat = 0;

double totalSugar = 0;

double totalProtein = 0;

// Keep parsing through input

while( !(input = keyboard.nextLine()).equals("STOP") ) {

inputTokenizer = new StringTokenizer(input);

String name = inputTokenizer.nextToken();

double amount = Double.parseDouble(inputTokenizer.nextToken());

// Check if it matches any of the items in the inventory

for(int i = 0; i < inventory.totalFoodItems; i++) {

if(inventory.foodItems[i].getName().equals(name)) {

if (inventory.foodItems[i].decreaseStock(amount)){

totalPrice += amount * inventory.foodItems[i].getPrice();

totalFat += amount * inventory.foodItems[i].getFat() * inventory.foodItems[i].getCaloriesPerUnit();

totalSugar += amount * inventory.foodItems[i].getSugar() * inventory.foodItems[i].getCaloriesPerUnit();

totalProtein += amount * inventory.foodItems[i].getProtein() * inventory.foodItems[i].getCaloriesPerUnit();

break;

}

}

}

}

keyboard.close();

// Print results

System.out.printf("Total price: $%.2f ", totalPrice);

System.out.printf("Total calories from fat: $%.2f calories ", totalFat );

System.out.printf("Total calories from sugar: $%.2f calories ", totalSugar);

System.out.printf("Total calories from protein: $%.2f calories ", totalProtein);

System.out.println("");

System.out.println("Inventory:");

System.out.println("");

inventory.printInventory();

}

// Add a food item to the inventory

public boolean addFoodItem(Food f) {

// List is full

if(totalFoodItems >= maxFoodItems) {

return false;

}

foodItems[totalFoodItems] = f;

totalFoodItems++;

return true;

}

public void printInventory() {

for(int i = 0; i < totalFoodItems; i++) {

System.out.println(foodItems[i].toString());

}

}

}