Shopping Cart API

Project Overview

This is a Java REST API to handle a shopping cart and apply the "Get 3 for the price of 2" promotion. The API allows users to add and remove items from the shopping cart and calculate the total price with the promotion applied. It is also possible to clear the cart.

Architecture and Design

The project follows a simple and straightforward architecture, consisting of the following components:

1. Controller: The CartController class is responsible for handling incoming HTTP requests and defining the API endpoints.

2. Service: The CartServiceImpl class contains the business logic for adding, removing items, clearing the cart and calculating the total price with the promotion.

3. Domain -> Entity: The Cart and Product classes represents the Cart and the Item, respectively.

4. Domain -> DTO: The ProductRequest and CheckoutResponse classes handle the endpoints input and output.

5. Exception: The InvalidAmountException and InvalidProductException classes represents custom exceptions for handling errors.

6. Database: The project uses a mocked Database to define the items available in the store. The source is resources/fake_products_database.json

How to Run the Project

1. Clone the repository or download the source code.

2. Open the project in your preferred Java IDE.

3. Build the project to resolve the dependencies.

4. Run the Main class to start the API.

API Endpoints

Add Item to Shopping Cart

• HTTP Method: POST
• Endpoint: /api/shopping-cart/v1/cart/product'
• Request Body:

  {
    "productId": "1",
    "amount": 3
  }
  

• Response: Status 200 OK

Remove Item from Shopping Cart

• HTTP Method: DELETE
• Endpoint: /api/shopping-cart/v1/cart/product'
• Request Body:

  {
    "productId": "1",
    "amount": 3
  }
  

• Response: Status 200 OK

Clear Shopping Cart

• HTTP Method: DELETE
• Endpoint: /api/shopping-cart/v1/cart/clear
• Response: Status 200 OK

Checkout the Shopping Cart

• HTTP Method: GET
• Endpoint: /api/shopping-cart/v1/cart/checkout'
• Response: Status 200 OK

  {
    "cart": [
      {
       "productId": "1",
        "amount": 3
      }
  ],
    "totalPrice": 25.98
  }