Code for the Amazon Online Shopping System

Write the object-oriented code to implement the design of the Amazon problem.

We'll cover the following

Amazon classes
Wrapping up

We’ve gone over the different aspects of Amazon and observed the attributes attached to the problem using various UML diagrams. Let’s explore the more practical side of things, where we’ll implement Amazon using multiple languages. This is usually the last step in an object-oriented design interview process.

We have chosen the following languages to write the skeleton code of the different classes present in Amazon:

Java
C#
Python
C++
JavaScript

Amazon classes#

In this section, we’ll provide the skeleton code of the classes designed in the class diagram lesson.

Note: For simplicity, we are not defining getter and setter functions. The reader can assume that all class attributes are private and accessed through their respective public getter methods and modified only through their public method functions.

Constants#

The following code provides the definition of the various enums and custom data types being used in the Amazon design:

Note: JavaScript does not support enumerations so we will be using the Object.freeze() method as an alternative that freezes an object and prevents further modifications.

public class Address {
  private int zipCode;
  private String address;
  private String city;
  private String state;
  private String country;
}
enum OrderStatus {
  UNSHIPPED, 
  PENDING, 
  SHIPPED, 
  CONFIRMED, 
  CANCELED, 
  REFUNDED
}
enum AccountStatus {
  ACTIVE, 
  INACTIVE, 
  BLOCKED
}
enum ShipmentStatus {
  PENDING, 
  SHIPPED, 
  DELIVERED, 
  ON_HOLD
}
enum PaymentStatus {

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Constant definitions

public class Account {
  private String userName;
  private String password;
  private String name;
  private List<Address> shippingAddress;
  private AccountStatus status;
  private String email;
  private String phone;
  private List<CreditCard> creditCards;
  private List<ElectronicBankTransfer> bankAccounts;
  public Address getShippingAddress();
  public boolean addProduct(Product product);
  public boolean addProductReview(ProductReview review, Product product);
  public boolean deleteProduct(Product product);
  public boolean deleteProductReview(ProductReview review, Product product);
  public boolean resetPassword();
}

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The Account class

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The Admin class

// Customer is an abstract class
public abstract class Customer {
  private ShoppingCart cart;
  public abstract ShoppingCart getShoppingCart();
}
public class Guest extends Customer {
  public boolean registerAccount();
  public ShoppingCart getShoppingCart() {
    // functionality
  }
}
public class AuthenticatedUser extends Customer {
  private Account account;
  private Order order;
  public OrderStatus placeOrder(Order order);
  public ShoppingCart getShoppingCart() {
    // functionality
  }
}

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Customer and its child classes

public class Product {
  private String productId;
  private String name;
  private String description;
  private byte[] image;
  private double price;
  private ProductCategory category;
  private List<ProductReview> reviews;
  private int availableItemCount;
  private Account account;
  public int getAvailableCount();
  public int updateAvailableCount();
  public boolean updatePrice(double newPrice);
}
public class ProductCategory {
  private String name;
  private String description;
  private List<Product> products;
}
public class ProductReview {
  private int rating;
  private String review;
  private byte[] image;
  private AuthenticatedUser user;
}

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The Product, ProductCategory, and ProductReview classes

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The ShoppingCart and CartItem classes

public class Order {
  private String orderNumber;
  private OrderStatus status;
  private Date orderDate;
  private List<OrderLog> orderLog;
  private ShoppingCart shoppingCart;
  public boolean sendForShipment();
  public boolean makePayment(Payment payment);
  public boolean addOrderLog(OrderLog orderLog);
}
public class OrderLog {
  private String orderNumber;
  private Date creationDate;
  private OrderStatus status;
}

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The Order and OrderLog classes

public class Shipment {
  private String shipmentNumber;
  private Date shipmentDate;
  private Date estimatedArrival;
  private String shipmentMethod;
  private List<ShipmentLog> shipmentLogs;
  public boolean addShipmentLog(ShipmentLog shipmentLog);
}
public class ShipmentLog {
  private String shipmentNumber;
  private Date creationDate;
  private ShipmentStatus status;
}

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The Shipment and ShipmentLog classes

// Payment is an abstract class
public abstract class Payment {
  private double amount;
  private Date timestamp;
  private PaymentStatus status;
  public abstract PaymentStatus makePayment();
}
public class CreditCard extends Payment {
  private String nameOnCard;
  private String cardNumber;
  private String billingAddress;
  private int code;
  public PaymentStatus makePayment() {
      // functionality
  }
}
public class ElectronicBankTransfer extends Payment {
  private String bankName;
  private String routingNumber; 
  private String accountNumber;
  private String billingAddress;
  public PaymentStatus makePayment() {
      // functionality
  }
}
public class Cash extends Payment {
  private String billingAddress;
  public PaymentStatus makePayment() {

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Payment and its child classes

// Notification is an abstract class
public abstract class Notification {
  private int notificationId;
  private Date createdOn;
  private String content;
  public abstract boolean sendNotification(Account account);
}
public class EmailNotification extends Notification {
  public boolean sendNotification(Account account) {
    // functionality 
  }
}
public class PhoneNotification extends Notification {
  public boolean sendNotification(Account account) {
    // functionality 
  }
}

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Notification and its child classes

public interface Search {
  public List<Product> searchProductsByName(String name);
  public List<Product> searchProductsByCategory(String category);
}
public class Catalog implements Search {
  private HashMap<String, List<Product>> products;
  public List<Product> searchProductsByName(String name) {
    // functionality
  }
  public List<Product> searchProductsByCategory(String category) {
    // functionality
  }
}

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The Search interface and Catalog class

Activity Diagram for the Amazon Online Shopping System

Getting Ready: Stack Overflow