Task Manager API

A RESTful task management service built with Kotlin and Spring Boot. Uses Spring WebFlux for reactive HTTP handling, JdbcClient with native SQL for data access, and Flyway for database migrations.

Tech Stack

• Kotlin 1.9 / JDK 21
• Spring Boot 3.5
• Spring WebFlux (Netty)
• Spring JDBC (JdbcClient)
• Project Reactor (Mono)
• H2 in-memory database
• Flyway

Project Structure

src/main/kotlin/com/taskmanager/task_manager/
├── controller/        # REST endpoints
├── service/           # Business logic, Reactor wrappers
├── repository/        # JdbcClient + native SQL
├── model/             # Task entity, TaskStatus enum
├── dto/               # Request/response DTOs, mapper
└── exception/         # TaskNotFoundException, GlobalExceptionHandler

Prerequisites

• JDK 21

Running the Application

./gradlew bootRun

The app starts on http://localhost:8080.

Running Tests

./gradlew test

Covers service layer (7 tests) and controller layer (8 tests).

API Reference

Create a task

POST /api/tasks

{
  "title": "Prepare report",
  "description": "Monthly financial report"
}

Response: 201 Created

{
  "id": 1,
  "title": "Prepare report",
  "description": "Monthly financial report",
  "status": "NEW",
  "createdAt": "2026-03-26T12:00:00",
  "updatedAt": "2026-03-26T12:00:00"
}

---

Get all tasks

GET /api/tasks?page=0&size=10&status=NEW

• page and size are required
• status is optional — one of NEW, IN_PROGRESS, DONE, CANCELLED
• Results are sorted by createdAt descending

Response: 200 OK

{
  "content": [...],
  "page": 0,
  "size": 10,
  "totalElements": 1,
  "totalPages": 1
}

---

Get task by ID

GET /api/tasks/{id}

Response: 200 OK or 404 Not Found

---

Update task status

PATCH /api/tasks/{id}/status

{
  "status": "DONE"
}

Response: 200 OK with updated task

---

Delete a task

DELETE /api/tasks/{id}

Response: 204 No Content

Validation

• title is required, must be between 3 and 100 characters
• Invalid requests return 400 Bad Request with field-level error messages

Notes

• Database is in-memory (H2), data resets on restart
• H2 console available at http://localhost:8080/h2-console (JDBC URL: jdbc:h2:mem:taskdb)