Hexagonal Java Project

This project is an example of implementing a hexagonal architecture using Java and Spring Boot. It includes a basic setup for user and product management, demonstrating principles of SOLID and clean architecture.

Features

• Hexagonal Architecture: The project follows the hexagonal architecture pattern to separate the core logic from the infrastructure.
• Spring Boot: Utilizes Spring Boot for application setup and configuration.
• H2 Database: Uses H2 in-memory database for data persistence.
• RESTful API: Provides a RESTful API for managing users and products.
• DTO Layer: Includes a Data Transfer Object (DTO) layer for data validation and transfer.
• JUnit Tests: Comprehensive tests for application, domain, and infrastructure layers.

Technologies Used

• Java 22: Core programming language.
• Spring Boot 3.1.1: Framework for building the application.
• H2 Database: In-memory database for development and testing.
• JUnit 5: Framework for unit and integration testing.

Project Structure

hexagonal-java-project/
├── src/
│   ├── main/
│   │   ├── java/
│   │   │   ├── com/
│   │   │   │   └── example/
│   │   │   │       ├── application/
│   │   │   │       │   ├── controller/
│   │   │   │       │   └── dto/
│   │   │   │       ├── domain/
│   │   │   │       │   ├── model/
│   │   │   │       │   ├── service/
│   │   │   │       │   └── port/
│   │   │   │       ├── infrastructure/
│   │   │   │       │   ├── adapter/
│   │   │   │       │   ├── entity/
│   │   │   │       │   ├── mapper/
│   │   │   │       │   └── repository/
│   │   │   │       └── HexagonalJavaApplication.java
│   ├── resources/
│   │   └── application.properties
│   ├── test/
│   │   ├── java/
│   │   │   └── com/
│   │   │       └── example/
│   │   │           ├── application/
│   │   │           │   ├── controller/
│   │   │           ├── domain/
│   │   │           │   ├── service/
│   │   │           ├── infrastructure/
│   │   │           │   ├── adapter/
│   │   │           │   └── repository/
├── pom.xml

Folder Responsibilities

• application: Contains the application's entry points, such as controllers and DTOs.

  • controller: Defines RESTful API endpoints.
  • dto: Data Transfer Objects used for data validation and transfer between layers.

• domain: Contains the core business logic and domain models.

  • model: Defines the main business entities.
  • service: Implements the business logic and use cases.
  • port: Defines interfaces for the application to interact with the infrastructure (e.g., repository interfaces).

• infrastructure: Contains the implementation details and external system integrations.

  • adapter: Implements the interfaces defined in the domain layer, providing the actual interaction with the database.
  • entity: Defines the JPA entities corresponding to the database tables.
  • mapper: Contains mappers to convert between domain models and entities.
  • repository: JPA repository interfaces for data access.

• HexagonalJavaApplication.java: The main class that starts the Spring Boot application.

Getting Started

Prerequisites

• Java 22
• Maven 3.9.8

Installation

1. Clone the repository:

git clone https://github.com/j-e-0/scaffold-hexagonal-pattern-java
cd scaffold-hexagonal-pattern-java

2. Build the project:

mvn clean install

3. Run the application:

mvn spring-boot:run

Configuration

The application is configured to use the H2 in-memory database by default. The configuration can be found in the src/main/resources/application.properties file.

# H2 Database
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=password
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.h2.console.enabled=true

Running Tests

To run the tests, use the following command:

mvn test

API Endpoints

The project exposes the following RESTful API endpoints:

Users

• GET /api/v1/users - Get all users
• GET /api/v1/users/{id} - Get user by ID
• POST /api/v1/users - Create a new user
• DELETE /api/v1/users/{id} - Delete user by ID

Products

• GET /api/v1/products - Get all products
• GET /api/v1/products/{id} - Get product by ID
• POST /api/v1/products - Create a new product
• DELETE /api/v1/products/{id} - Delete product by ID

Contributing

Contributions are welcome! Please fork the repository and create a pull request with your changes.

License

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