🛒 Ecommerce API

A RESTful API for a simplified e-commerce platform built with Java 17, Spring Boot 3, PostgreSQL, and Docker. This project demonstrates domain modeling, relational database relationships, and business logic implementation using modern Java backend technologies.

📌 Features

• User registration with automatic cart creation
• Product and category management (CRUD)
• Shopping cart with add/remove items
• Order checkout with automatic total calculation
• Fake payment processing with automatic approval
• Relational data modeling with JPA/Hibernate

🛠️ Tech Stack

Technology	Version
Java	17
Spring Boot	3.5.11
Spring Data JPA	-
Hibernate	6.x
PostgreSQL	16
Docker	-
Lombok	-
Maven	3.x

📦 Project Structure

src/main/java/com/oskar/ecommerce_api/
├── controller/       # REST endpoints
├── entity/           # JPA entities (database tables)
├── enums/            # OrderStatus, PaymentStatus
├── exception/        # Error handling
├── repository/       # Data access layer
└── service/          # Business logic

🗄️ Database Schema

• users — registered users
• carts — one cart per user (created automatically)
• cart_items — products inside a cart
• categories — product categories
• products — product catalog
• orders — placed orders
• order_items — products inside an order (with price snapshot)
• payments — payment record per order

🚀 Getting Started

Prerequisites

• Java 17
• Docker

Run the database

docker compose up postgres -d

Run the application

./mvnw spring-boot:run

The API will be available at http://localhost:8080

📡 API Endpoints

Users

Method	Endpoint	Description
GET	/api/users	List all users
GET	/api/users/{id}	Get user by ID
POST	/api/users	Create user
DELETE	/api/users/{id}	Delete user

Categories

Method	Endpoint	Description
GET	/api/categories	List all categories
GET	/api/categories/{id}	Get category by ID
POST	/api/categories	Create category
DELETE	/api/categories/{id}	Delete category

Products

Method	Endpoint	Description
GET	/api/products	List all products
GET	/api/products/{id}	Get product by ID
POST	/api/products	Create product
PUT	/api/products/{id}	Update product
DELETE	/api/products/{id}	Delete product

Cart

Method	Endpoint	Description
GET	/api/cart/{userId}	Get cart by user
POST	/api/cart/{userId}/items?productId=&quantity=	Add item to cart
DELETE	/api/cart/{userId}/items/{productId}	Remove item from cart

Orders

Method	Endpoint	Description
POST	/api/orders/checkout/{userId}	Checkout and place order
GET	/api/orders/user/{userId}	List orders by user

📋 Usage Example

1. Create a user

POST /api/users
{
    "name": "John Doe",
    "email": "john@email.com"
}

2. Create a category

POST /api/categories
{
    "name": "Electronics"
}

3. Create a product

POST /api/products
{
    "name": "Laptop",
    "description": "Gaming laptop",
    "price": 1500.00,
    "stock": 10,
    "category": {"id": 1}
}

4. Add product to cart

POST /api/cart/1/items?productId=1&quantity=2

5. Checkout

POST /api/orders/checkout/1

👤 Author

José Oskarithio Fernandes
Backend Developer | Java & Python
GitHub