Sample vending machine made in Java (classification)

The vending machine I wrote last time: https://qiita.com/TakumiKondo/items/e93aa60031e2fe09d969 Was classified into classes.

Items.java

package vm;
 
import java.util.HashMap;
import java.util.Map;
 
public class Items {
    private Map<String, Integer> items; //Product List
    private Map<String, Integer> availablePurchases; //Items that can be purchased
 
    //Constructor (initialization of product list)
    Items() {
        this.items = new HashMap<String, Integer>();
        items.put("Cola", 100);
        items.put("Orange juice", 120);
        items.put("water", 80);
    }
 
    //Get the minimum purchase price
    int minPrice() {
        int minPrice = 0;
        int loopCount = 0;
        for (String itemKey : items.keySet()) {
            minPrice = validMinPrice(loopCount, minPrice, itemPrice(itemKey));
            loopCount++;
        }
        return minPrice;
    }
 
    //Judgment of minimum purchase amount
    int validMinPrice(int loopCount, int minPrice, int price) {
        if (loopCount == 0 || minPrice > price) {
            minPrice = price;
        }
        return minPrice;
    }
 
    //Product price
    private int itemPrice(String itemKey) {
        return items.get(itemKey);
    }
 
    //Amount of items that can be purchased
    private int availablePurchasePrice(String itemKey) {
        return availablePurchases.get(itemKey);
    }
 
    //Get a list of available products
    void createAvailablePurchases(int deposit) {
        availablePurchases = new HashMap<String, Integer>();
        for (String itemKey : items.keySet()) {
            addAvailablePurchase(deposit, itemKey);
        }
    }
 
    //Addition of available product list
    private void addAvailablePurchase(int deposit, String itemKey) {
        if (deposit >= items.get(itemKey)) {
            availablePurchases.put(itemKey, items.get(itemKey));
        }
    }
 
    //Display of available products
    void showAvailablePurchase() {
        for (String itemKey : availablePurchases.keySet()) {
            System.out.println(itemKey + ":" + items.get(itemKey) + "Circle");
        }
    }
 
    //Judgment as to whether the product is available for purchase
    boolean isAvailablePurchase(String itemName, Deposit deposit) {
        return availablePurchases.containsKey(itemName);
    }
 
    //Selling price
    int saleAmount(String itemName) {
        return availablePurchasePrice(itemName);
    }
}

Deposit.java

package vm;
 
public class Deposit {
    private int deposit; //Deposit amount
 
    //Constructor (initial value 0 yen)
    Deposit() {
        deposit = 0;
    }
 
    //payment
    void deposit(int amount) {
        deposit = deposit + amount;
    }
 
    //Current deposit amount
    int amount() {
        return this.deposit;
    }
 
    //Billing
    void charge(int amount) {
        int charge = this.deposit - amount;
        this.deposit = charge;
    }
}

VendingMachine.java

package vm;
 
public class VendingMachine {
    private Items items; //Product
    private Deposit deposit; //Deposit amount
 
    //constructor
    VendingMachine() {
        items = new Items();
        deposit = new Deposit();
    }
 
    //payment
    void deposit(int amount) {
        deposit.deposit(amount);
    }
 
    //Determine if there is a deposit above the lowest priced item
    boolean hasMinDeposit() {
        if (deposit.amount() < items.minPrice()) {
            return false;
        }
        return true;
    }
 
    //Show available items
    void showAvailablePurchases() {
        items.createAvailablePurchases(deposit.amount());
        items.showAvailablePurchase();
    }
 
    //Determine if the item is available for purchase
    boolean isAvailablePurchases(String itemName) {
        return items.isAvailablePurchase(itemName, deposit);
    }
 
    //Show purchased items
    void selectItem(String itemName) {
        System.out.println(itemName + "is!");
    }
 
    //Billing
    void charge(String itemName) {
        int saleAmount = items.saleAmount(itemName);
        deposit.charge(saleAmount);
        System.out.println("Change is" + deposit.amount() + "It is a circle.");
    }
}

Main.java

package vm;
 
import java.util.Scanner;
 
/**
 *Vending Machine (Level 6) Creating Vending Machine Class
 */
public class Main {
    //Main logic
    public static void main(String[] args) {
        //① Product initialization
        VendingMachine vendingMachine = new VendingMachine();
 
        //Additional deposit for minimum purchase amount
        Scanner scanner = new Scanner(System.in);
        do {
            //② Deposit
            System.out.println("Please put in the money.");
            int amount = scanner.nextInt();
            vendingMachine.deposit(amount);
 
            //③ Amount check (minimum purchase amount)
        } while (!vendingMachine.hasMinDeposit());
 
        //④ Display available products
        System.out.println("");
        System.out.println("It is a product that can be purchased.");
        vendingMachine.showAvailablePurchases();
 
        //⑤ Select a product
        String itemName;
        do {
            System.out.println("");
            System.out.println("Please enter the product name.");
            itemName = scanner.next();
        } while (!vendingMachine.isAvailablePurchases(itemName));
        vendingMachine.selectItem(itemName);
        scanner.close();
 
        //⑥ Billing function
        vendingMachine.charge(itemName);
    }
 
}