Online e-commerce Application

Introduction

This is a microservices-based online e-commerce application built with Spring Boot, Spring Cloud, and other modern technologies. The application provides a complete e-commerce solution with features like product browsing, cart management, order processing, payment integration, and more.

Microservices Architecture

The application is built using a microservices architecture, which consists of the following services:

• User Service: Manages user profiles, authentication, and authorization
• Product Service: Handles product catalog, categories, and inventory
• Cart Service: Manages e-commerce carts
• Order Service: Processes and tracks orders
• Payment Service: Handles payment processing
• Notification Service: Sends notifications to users
• Auth Service: Manages authentication and authorization with Keycloak integration
• Gateway Service: API Gateway for routing requests to appropriate services
• Config Server: Centralized configuration management
• Discovery Service: Service discovery with Eureka

Tech Stack

• Java 24: Latest Java version for optimal performance
• Spring Boot 3.4.2: Modern framework for building Java applications
• Spring Cloud 2024.0.0: Tools for building cloud-native applications
• Spring Security: Authentication and authorization
• Keycloak: Identity and access management
• Kafka: Event-driven communication between services
• Redis: Caching and session management
• PostgreSQL: Primary database for most services
• MongoDB: Alternative database for certain services requiring flexible schema
• Resilience4j: Circuit breaking and fault tolerance
• MapStruct: Object mapping between DTOs and domain models
• Micrometer & Zipkin: Distributed tracing
• ELK Stack: Centralized logging
• Prometheus & Grafana: Monitoring and visualization
• Docker & Docker Compose: Containerization and orchestration
• JUnit & Mockito: Testing framework

Domain Driven Design (DDD)

This application follows Domain Driven Design principles:

• Bounded Contexts: Each microservice represents a bounded context
• Entities & Value Objects: Core domain objects
• Aggregates: Ensuring data consistency
• Domain Events: Communicating between bounded contexts
• Repositories: Data access abstraction
• Domain Services: Complex business logic spanning multiple entities

Security

Security is implemented using:

• Spring Security: For authentication and authorization
• Keycloak: Identity and Access Management
• JWT: Token-based authentication
• OAuth2: Authorization framework
• Role-Based Access Control: Different access levels for different user roles

Features

User Management

• User registration and login
• Profile management
• Address management
• Role-based access control

Product Management

• Product catalog
• Categories and subcategories
• Product search and filtering
• Product reviews and ratings

e-commerce

• Add products to cart
• View and edit cart
• Checkout process
• Order tracking
• Payment processing

Admin Dashboard

• Inventory management
• Order management
• User management
• Analytics and reporting

Getting Started

Prerequisites

• Java 24
• Docker and Docker Compose
• Maven

Running Locally

1. Clone the repository
2. Start the infrastructure services:

   docker-compose up -d
   

3. Build the application:

   mvn clean install
   

4. Start the services in order:
   • Config Server
   • Discovery Service
   • Auth Service
   • Other services

Using Docker

Simply run:

docker-compose up -d

This will start all services and required infrastructure.

API Documentation

API documentation is available through Swagger UI at:

http://localhost:9090/swagger-ui.html

Future Enhancements

• Recommendation Engine: Personalized product recommendations
• Internationalization: Multi-language support
• Multi-tenancy: Support for multiple shops on the same platform
• Advanced Analytics: AI-powered sales predictions
• Mobile App Integration: APIs for mobile applications
• Content Management: Rich content for products

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Profiles

The application supports two profiles:

1. default: Uses localhost for all service connections (development on local machine)
2. dev: Uses Docker container names for service discovery (running in Docker)

Starting the Application

You can start the application in two ways:

Local Development (default profile)

./start-services.sh

This will:

• Start infrastructure services (Postgres, MongoDB, Redis, Kafka) using Docker
• Start all microservices locally with the default profile
• Use local application.properties files for configuration

With a Specific Profile

./start-services.sh dev

This will start all services with the dev profile.

Using Docker for All Services

./start-services.sh dev true

This will:

• Start all services (infrastructure and application) using Docker Compose
• Configure them to use the dev profile

Using Config Server

./start-services.sh default false true

This will:

• Start infrastructure services (Postgres, MongoDB, Redis, Kafka) using Docker
• Start the Config Server
• Start all other services configured to use the centralized configuration

You can combine all options:

# Format: ./start-services.sh [profile] [use-docker] [use-config-server]
./start-services.sh dev true true

This will:

• Start all services using Docker
• Configure them to use the dev profile
• Use the Config Server for configuration

Stopping the Application

To stop all services:

./stop-services.sh

If you started with Docker for all services:

./stop-services.sh true

Accessing the Application

• API Gateway: http://localhost:8765
• Discovery Service Dashboard: http://localhost:8761
• Swagger API Documentation: http://localhost:8765/swagger-ui.html

Configuration

Each service has its own configuration in:

• Individual service configuration:

  • src/main/resources/application.properties - Default configuration
  • src/main/resources/application-dev.properties - Docker environment configuration

• Centralized configuration (Config Server):

  • config-server/src/main/resources/config/<service-name>.yml - Contains both default and dev profile configurations

Using the Config Server

The Config Server provides centralized configuration for all services. Each service can load its configuration from the Config Server when spring.cloud.config.enabled=true is set.

To use the Config Server:

1. Make sure the Config Server is running: cd config-server && java -jar target/config-server-0.0.1-SNAPSHOT.jar
2. Start services with Config Server enabled: java -Dspring.cloud.config.enabled=true -jar <service-jar>

You can see the configurations at:

• Config Server API: http://localhost:8888//default
• Config Server API (dev profile): http://localhost:8888//dev

Development

To add a new service:

1. Create a new Spring Boot project
2. Add the necessary dependencies for Spring Cloud
3. Create both application.properties and application-dev.properties
4. Update the docker-compose.yml file if needed