Online Shop API

REST API for an online store built with Spring Boot 3 and Java 17. A portfolio project showcasing clean architecture, professional engineering practices, and conscious technical decisions.

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Features

• Clean layered architecture (Controller → Service → Repository)
• Complete separation of concerns – no JPA entities exposed outside the service layer
• DTOs implemented as Java Records
• Mapping with MapStruct
• Database schema management with Flyway
• Integration tests with Testcontainers (real PostgreSQL, no H2)
• Price and product data snapshots in orders (historical consistency)
• Guest checkout support
• Global exception handling using RFC 7807 (Problem Detail)
• Spring Boot Actuator with health, info and metrics
• Comprehensive API documentation with Swagger UI
• Well-structured unit and integration tests

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Technologies

• Java 17
• Spring Boot 3.5
• Spring Data JPA & Hibernate 6
• PostgreSQL 16
• Flyway
• MapStruct
• Lombok
• Testcontainers
• Swagger / OpenAPI 3
• Docker & Docker Compose

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How to Run

# 1. Clone the repository
git clone https://github.com/marand85/online-shop.git
cd online-shop

# 2. Start the application with Docker Compose (PostgreSQL + Backend)
cd infra
docker compose up -d

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

Interactive API documentation:
http://localhost:8080/swagger-ui.html

API Endpoints

Method	Endpoint	Description
GET	/api/categories	Get all categories
GET	/api/products	Get products (paginated, filtered, searchable)
GET	/api/products/{id}	Get product details
POST	/api/orders	Create new order (guest checkout)
GET	/api/orders/{orderNumber}	Get order by order number

Testing

The project includes both unit and integration tests:

• Unit tests – OrderServiceTest
• Integration tests – OrderControllerIT, CategoryRepositoryIT (using Testcontainers with real PostgreSQL)

Run tests with:

./mvnw test

Architecture Highlights

• Strict separation between domain models and API contracts
• No @Data on JPA entities (conscious decision to avoid equals()/hashCode() pitfalls)
• open-in-view: false to prevent lazy loading issues
• Price snapshots in order items to ensure historical consistency
• Deterministic test data with explicit IDs

Author

Mariusz Andrzejewski

• GitHub: https://github.com/marand85

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This project is part of a three-project portfolio, each demonstrating different skills:

• This project – Clean REST API architecture and testing
• Blog – Spring MVC + Thymeleaf (SSR)
• Banking System – Event-driven architecture with Kafka and microservices