Clean Architecture Backend - KOtlin

Backend Project in Clean Architecture using Kotlin, Spring Boot, Maven, jOOQ (and jOOQ code generation), Flyway and JWT Authentication

Project Structure

CAB-KO                     (root module / builder)
├─ Adapters/
│   ├─ Controllers         (module)
│   ├─ Presenter           (module)
│   └─ Repository          (module)
├─ Business/
│   ├─ Core                (module)
│   └─ UseCases            (module)
├─ Pom-Parent              (module)
└─ WebApp                  (module)
docker-compose-postgresql  (Docker setup for local PostgreSQL)
README.md                  (you’re reading)
pom.xml                    (root aggregator POM)

What this project does

This is a backend application built with:

• Kotlin + Maven
• Spring Boot (for the web and application layer)
• jOOQ (type-safe SQL code generation)
• Flyway (database migrations)
• JWT authentication

It uses a Clean Architecture style separation into modules: domain (Core), application (UseCases), adapters (Controllers, Presenter, Repository), and the startup module (WebApp).

Build & Run Instructions

Prerequisites

• Maven 3+
• Java 21
• Docker (for local PostgreSQL)

Build the full project

From the project root directory: mvn clean install

Run locally

From the project root directory: mvn -pl WebApp spring-boot:run This launches the WebApp module which depends on all other modules.

Access the application

Once started, open: http://localhost:8080

Accessing the Dockerized Database

• JDBC URL: jdbc:postgresql://localhost:5432/db_cabko
• Username: cabko
• Password: cabko

Default credentials

Use the following to authenticate:

POST http://localhost:8080/api/auth/login

Payload:
{
  "email": "admin@exemple.com",
  "password": "admin"
}

You will receive a JWT token. Include it in protected endpoints via header: Authorization: Bearer <YOUR_TOKEN>

Important Details

• Database migrations (Flyway) are located at: Adapters/Repository/src/main/resources/db/migration/
• The Repository module must be compiled to generate jOOQ code.
• The WebApp module is the executable module; all modules are modularized for separation of concerns.

Why this architecture

• Clean Architecture ensures that domain logic is isolated from frameworks, making it easier to adapt or evolve the system.
• Modules remain loosely coupled, improving testability and maintainability.
• Centralized parent POM simplifies version management and build configuration across modules.

Next Steps & Documentation

• Each module has its own README.md describing its role, dependencies and how to build/test it.
• For detailed configuration (e.g., JWT settings, database connection), consult application.properties in the WebApp module.