techlinks.in
Low Level Design (LLD) Coding

Follow

Low Level Design (LLD) Coding

Follow
Design (LLD) a Vending machine - Machine Coding

Design (LLD) a Vending machine - Machine Coding

techlinks.in's photo
techlinks.in
·Feb 20, 2022·

3 min read

Play this article

Table of contents

  • Vending Machine
  • Rough Solution (LLD-Machine Coding)

My project (1).png

Vending Machine

What is Vending Machine ? A vending machine is an automated machine that provides items such as snacks, beverages, cigarettes, and lottery tickets to consumers after cash, a credit card, or other forms of payment are inserted into the machine or otherwise made.

Low-level design (LLD) for a vending machine:

  1. Hardware interface: The vending machine will need to interface with the physical components such as the coin acceptor, bill acceptor, product dispenser, and display screen. This will likely involve creating classes or functions to handle input from these components and control the output to them.

  2. Payment processing: The vending machine will need to be able to accept and process payments from customers. This will involve implementing logic to accept and validate coins, bills, and possibly other forms of payment such as credit cards or mobile payments.

  3. Product inventory: The vending machine will need to track the available products and their quantities. This will likely involve creating a database or data structure to store this information, as well as functions to update the inventory when products are dispensed.

  4. Dispensing logic: The vending machine will need to be able to dispense the selected product to the customer when a valid payment is made. This will involve creating functions to control the product dispenser and update the inventory when a product is dispensed.

  5. User interface: Finally, we will need to design the user interface for the vending machine, including the layout, navigation, and any necessary graphics or styling. This will involve creating wireframes and mockups, as well as implementing the front-end code to bring the design to life.

Rough Solution (LLD-Machine Coding)

Here is a possible low-level design (LLD) for a vending machine in Java:

public class VendingMachine {
    private ItemDatabase itemDatabase;
    private PaymentProcessor paymentProcessor;
    private Dispenser dispenser;
    private Display display;
    private CoinAcceptor coinAcceptor;
    private CardReader cardReader;

    public VendingMachine() {
        itemDatabase = new ItemDatabase();
        paymentProcessor = new PaymentProcessor();
        dispenser = new Dispenser();
        display = new Display();
        coinAcceptor = new CoinAcceptor();
        cardReader = new CardReader();
    }

    public void addItem(Item item) {
        itemDatabase.addItem(item);
    }

    public void selectItem(String itemCode) {
        Item item = itemDatabase.getItem(itemCode);
        if (item == null) {
            display.displayMessage("Invalid item code");
            return;
        }
        if (item.getQuantity() == 0) {
            display.displayMessage("Item out of stock");
            return;
        }
        display.displayPrice(item.getPrice());
    }

    public void insertCoin(Coin coin) {
        paymentProcessor.addPayment(coin);
        display.displayBalance(paymentProcessor.getBalance());
    }

    public void insertCard(Card card) {
        paymentProcessor.addPayment(card);
        display.displayBalance(paymentProcessor.getBalance());
    }

    public void cancelTransaction() {
        paymentProcessor.cancelTransaction();
        display.displayMessage("Transaction canceled");
    }

    public void completeTransaction(String itemCode) {
        Item item = itemDatabase.getItem(itemCode);
        if (item == null) {
            display.displayMessage("Invalid item code");
            return;
        }
        if (item.getQuantity() == 0) {
            display.displayMessage("Item out of stock");
            return;
        }
        if (paymentProcessor.getBalance() < item.getPrice()) {
            display.displayMessage("Insufficient funds");
            return;
        }
        paymentProcessor.processPayment(item.getPrice());
        item.decrementQuantity();
        dispenser.dispenseItem(item);
        display.displayMessage("Transaction complete");
    }
}

public class ItemDatabase {
    private Map<String, Item> items;

    public ItemDatabase() {
        items = new HashMap<>();
    }

    public void addItem(Item item) {
        items.put(item.getCode(), item);
    }

    public Item getItem(String code) {
        return items.get(code);
    }
}
public class PaymentProcessor {
    private float balance;

    public void addPayment(Payment payment) {
        balance += payment.getAmount();
    }

    public void cancelTransaction() {
        balance = 0;
    }

    public void processPayment(float amount) {
        balance -= amount;
    }

    public float getBalance() {
        return balance;
    }
}

and CardReader classes of a vending machine in Java:

public class Dispenser {
    public void dispenseItem(Item item) {
        // Dispense the item
    }
}

public class Display {
    public void displayMessage(String message) {
        // Display the message on the display screen
    }

    public void displayPrice(float price) {
        // Display the price on the display screen
    }

    public void displayBalance(float balance) {
        // Display the balance on the display screen
    }
}
public class CoinAcceptor {
    public void acceptCoin(Coin coin) {
        // Accept the coin
    }
}

public class CardReader {
    public void readCard(Card card) {
        // Read the card information
    }
}

Did you find this article valuable?

Support techlinks.in by becoming a sponsor. Any amount is appreciated!

See recent sponsors Learn more about Hashnode Sponsors
 
Share this