Question

Given a snack vending machine, assume the machine accepts bills and coins, after customer input money and select items, the machine can calculate and dispose snack.

a. Finish a class diagram of the snack vending machine using correct UML notations.

b. Convert the class diagram above to Java code.

Answer 1

import java.util.Scanner;

public class VendingMachine
{
private Product[] items;

public VendingMachine() {
items = new Product[5];
items[0] = new Product("Chips", 20.0, 20);
items[1] = new Product("Pepsi", 40.0, 10);
items[2] = new Product("Mazza", 40.0, 10);
items[3] = new Product("Bingo", 40.0, 10);
items[4] = new Product("Dairy Milk", 20.0, 20);
}

public void displayInventory() {
for (int i = 0; i < items.length; i++)
{
System.out.print(items[i].getName());
System.out.print('\t');
System.out.print(items[i].getQty());
System.out.println();
}
}

public void Productdispenser(int itemCode) {
Scanner in = new Scanner(System.in);
if (items[itemCode].getQty() <= 0) {
System.out.println("Oops!.., out of stock"); // Check for stock
}
else
{
  
System.out.println("MRP: " + items[itemCode].getPrice()); // Prints MRP
System.out.print("Insert the coin: "); // Insert coin
double amt = in.nextDouble();
if (amt < items[itemCode].getPrice()) {
System.out.println("Insufficient money paid, can't dispense " +
items[itemCode].getName());
System.out.println("Refunding " + amt);
}
else
{
System.out.println("Dispensing one " + items[itemCode].getName());
double changeAmt = amt - items[itemCode].getPrice();
if (changeAmt > 0)
System.out.println("Here is your change amount of " + changeAmt);
items[itemCode].reduceQty();
}
}
}

Product[] getItems() {
return items;
}

public static void main(String args[])
{

Scanner in = new Scanner(System.in);
VendingMachine v = new VendingMachine();
Product[] Vending_Items = v.getItems();
  
  
System.out.println("Vending Machine Menu");
for (int i = 0; i < Vending_Items.length; i++)
{
System.out.println("Enter " + (i+1) + " for " + Vending_Items[i].getName()); // Display Product List with the MRP
}

System.out.println("Enter 6 to stop the Vending Machine");
  
int option;
do {
System.out.print("Enter your option: ");
option = in.nextInt();

if (option < 1 || option > 6) {
System.out.println("Incorrect...!! Please choose another option");
}
else if(option == 6) {
System.out.println("Stopping Vending Machine...Thank you");
}
else {
v.Productdispenser(option - 1);
}
} while(option != 6);

}
}
public class Product
{
private String name;
private double price;
private int qty;
  
public Product(String itemName, double itemPrice, int itemQty)
{
name = itemName;
price = itemPrice;
qty = itemQty;
}
  
public String getName() {
return name;
}
  
public double getPrice() {
return price;
}
  
public int getQty() {
return qty;
}
  
public void reduceQty() {
if (qty > 0)
qty -= 1;
}
}