*This program needs to simulate a vending machine.

In java using this code a vending machine program that uses an Interface.

public class Inventory {

private Map inventory = new HashMap();

public int getQuantity(T product) {

Integer value = inventory.get(product);

return value == null ? 0 : value;

}

public void add(T product) {

int count = inventory.get(product);

inventory.put(product, count + 1);

}

public void deduct(T product) {

if (hasItem(product)) {

int count = inventory.get(product);

inventory.put(product, count - 1);

}

}

public boolean hasItem(T product) {

return getQuantity(product) > 0;

}

public void clear() {

inventory.clear();

}

public void put(T product, int quantity) {

inventory.put(product, quantity);

}

}

public enum Product {

COKE("Coke", 25), PEPSI("Pepsi", 35), SODA("Soda", 45);

private String name;

private int price;

private Product (String name, int price) {

this.name = name;

this.price = price;

}

public String getName() {

return name;

}

public long getPrice() {

return price;

}

}