⭐ Product Reviews Microservice

This repository contains the Reviews & Ratings Service for the E-commerce ecosystem. It is a specialized microservice built to handle high-volume user feedback, comments, and interactions (likes/dislikes) using a non-relational database for scalability and flexibility.

🚀 Key Features

• Review Management: Users can create, update, and list reviews for products.
• Interaction System: Support for complex user interactions:
  • Comments: Nested discussions on specific reviews.
  • Reactions: Like and Dislike functionality for both Reviews and Comments.
• Aggregations: Efficient calculation of product rating averages and summaries using MongoDB Aggregation Framework.
• Event-Driven Updates: Utilizes RabbitMQ to handle reaction events asynchronously (e.g., updating counters when a review is liked).
• Reactive Security: JWT-based stateless authentication.

🛠️ Tech Stack

• Language: Java 21
• Framework: Spring Boot 3.5.3
• Database: MongoDB (NoSQL)
• Messaging: RabbitMQ
• Documentation: OpenAPI (Swagger UI)
• Build Tool: Gradle
• Observability: Prometheus & Micrometer

🏗️ Architecture

This service follows a Hexagonal/Clean Architecture approach with a strong focus on asynchronous processing.

src/main/java/com/example/productsreview/
├── api/            # REST Controllers (Entry points)
├── domain/         # Entities (Review, Comment) and Business Logic
├── listener/       # RabbitMQ Listeners (Event handlers)
├── repository/     # MongoDB Data Access Layer
└── service/        # Business Use Cases

Event System

The service relies on RabbitMQ to decouple high-frequency interactions.

• Listeners: ReviewReactionListener, CommentReactionListener.
• Events: ReviewLikedEvent, CommentAddedEvent, ProductRatingUpdatedEvent.

⚙️ Environment Configuration

Create a .env file in the root directory. You can use .env.example as a template:

# Authentication
ISSUER=your_auth_issuer_url

# MongoDB
MONGO_INITDB_ROOT_USERNAME=mongo
MONGO_INITDB_ROOT_PASSWORD=secret
SPRING_DATA_MONGODB_HOST=mongodb
SPRING_DATA_MONGODB_PORT=27017
SPRING_DATA_MONGODB_DATABASE=review_db

# RabbitMQ
RABBITMQ_DEFAULT_USER=guest
RABBITMQ_DEFAULT_PASS=guest
SPRING_RABBITMQ_HOST=rabbitmq
SPRING_RABBITMQ_PORT=5672

Note: Place your RSA keys (private_key.pem and public_key.pem) in src/main/resources/certs/ to enable JWT verification.

🐳 Running with Docker

This service is designed to run within the larger E-commerce docker network.

1. Ensure the shared network exists:

   docker network create shared_ecommerce_network

2. Start the service:

   docker-compose up -d --build

3. Access the Endpoints:

   • API Base: http://localhost:8081/reviews/api
   • Swagger Docs: http://localhost:8081/reviews/api/docs
   • Prometheus Metrics: http://localhost:8081/reviews/api/actuator/prometheus

📦 Manual Installation (Gradle)

If you prefer to run it locally without Docker (requires local MongoDB and RabbitMQ instances):

1. Build:

   ./gradlew clean build -x test

2. Run:

   java -jar build/libs/app.jar

📄 API Documentation

The API follows RESTful standards. You can explore the endpoints via Swagger UI running at /reviews/api/docs.

Key Endpoints:

• POST /reviews: Create a review.
• GET /reviews/product/{productId}: Get reviews for a product.
• POST /reviews/{reviewId}/comments: Add a comment.
• POST /reviews/{reviewId}/react: Like/Dislike a review.

🤝 Contributing

1. Fork the repository.
2. Create a feature branch (git checkout -b feature/NewFeature).
3. Commit your changes.
4. Push to the branch.
5. Open a Pull Request.