Hello everyone can any create a inventory management class for java for a vending machine that will do the following.

1. Upon selecting an item the inventory, the stock for the item reduces by 1.

2. Upon canceling a selection, the stock for the item should increase by 1.

3. Add a button that triggers the display of the entire inventory the inventory should be displayed in a separate grid pane.

?4. Add a button that shows total earnings.

This is the dispenser queue class below let me know if anything else is needed. Thank you.

import java.util.ArrayList;
	import javafx.scene.image.ImageView;
	public class DispenserQueue {
	String brand;
	String productName;
	String productClass;
	ArrayList slot;
	ImageView productImage;
	//Empty Queue Constructor
	public DispenserQueue() {
	slot = new ArrayList();
	productName = "empty";
	brand = "none";
	}
	//Initialized Queue
	public DispenserQueue(Product productType) {
	slot = new ArrayList();
	this.addProductToQueue(productType);
	productName = productType.getName();
	brand = productType.getBrand();
	productClass = slot.get(0).getProductClass();
	String imageName = productName + ".jpg";
	productImage = new ImageView(getClass().getResource(imageName).toExternalForm());
	//System.out.println( imageName + " Succeeded");
	}
	//Adds a single product to the queue
	public void addProductToQueue(Product productToAdd) {
	slot.add(productToAdd);
	productName = productToAdd.getName();
	}
	//Removes the specified product from the queue, ex: expiration date is passed, remove it.
	public void removeProductFromQueue(Product productToRemove) {
	slot.remove(productToRemove);
	}
	public String getProductType() {
	return brand;
	}
	public String getBrand() {
	return brand;
	}
	public void setBrand(String brand) {
	this.brand = brand;
	}
	public String getProductName() {
	return productName;
	}
	public void setProductName(String productName) {
	this.productName = productName;
	}
	public ArrayList getSlot() {
	return slot;
	}
	public void setSlot(ArrayList slot) {
	this.slot = slot;
	}
	public boolean isDrinkItem() {
	if(productClass.equals("Drink")) {
	return true;
	}
	else {
	return false;
	}
	}
	public boolean isChipsItem() {
	if(productClass.equals("Chips")) {
	return true;
	}
	else {
	return false;
	}
	}
	public boolean isCandyItem() {
	if(productClass.equals("Candy")) {
	return true;
	}
	else {
	return false;
	}
	}
	public boolean isGumItem() {
	if(productClass.equals("Gum")) {
	return true;
	}
	else {
	return false;
	}
	}
	public ImageView getProductImage() {
	return productImage;
	}
	}