The Catalog Service is a core microservice in the Smart Mart e-commerce platform, responsible for managing product categories and their hierarchical relationships. It provides a robust API for category management, including creation, retrieval, and hierarchical organization of product categories.

• Java 21 - Programming language
• Spring Boot 3.5.6 - Application framework
• Spring Data JPA - Data access
• PostgreSQL - Primary database
• Kafka - Event streaming
• Apache Avro - Data serialization

• Gradle - Build tool
• Lombok - Boilerplate reduction
• JUnit 5 - Testing framework
• Spring Test - Integration testing

The service follows a clean architecture pattern with clear separation of concerns:

com.smart.mart.catalog/
├── application/       # Application services and DTOs
├── domain/            # Domain model and business logic
└── infrastructure/    # Framework and external concerns
    ├── adapter/
    │   ├── input/     # REST controllers
    │   └── output/    # Persistence and external services
    └── config/        # Configuration classes

The core domain model includes:

• Category: Represents a product category with properties like name, description, and hierarchical relationships
• CategoryHierarchy: Manages parent-child relationships between categories

• POST /api/categories - Create a new category
• GET /api/categories/{id} - Get category by ID
• GET /api/categories - Get all categories (with optional filtering)
• PUT /api/categories/{id} - Update a category
• DELETE /api/categories/{id} - Delete a category

• POST /api/categories/{id}/subcategories - Add a subcategory
• GET /api/categories/{id}/hierarchy - Get category hierarchy

1. Request Handling: REST Controllers receive HTTP requests
2. Validation: Input validation using Spring Validation
3. Business Logic: Application services process requests
4. Persistence: Data is stored in PostgreSQL
5. Events: Domain events are published to Kafka for other services

• Java 21
• Gradle 8.0+
• PostgreSQL 13+
• Kafka 3.0+

1. Clone the repository
2. Configure database in application.yml
3. Start Kafka and create required topics
4. Run the application:

   ./gradlew bootRun

Run tests with:

./gradlew test

The test suite includes:

• Unit tests
• Integration tests
• Service layer tests
• Controller tests

Build the application:

./gradlew clean build

Create a Docker image:

./gradlew bootBuildImage

The service includes:

• Spring Boot Actuator endpoints for health checks and metrics
• Prometheus metrics
• Distributed tracing with OpenTelemetry

This project is licensed under the terms of the LICENSE file.