📝 Todo API

A RESTful API for task management built with Java 17 and Spring Boot 3.2.

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📌 About

Todo API is a backend project that implements a full CRUD for task management, following development best practices such as MVC pattern, layered architecture, DTOs, global exception handling, and data validation.

Built as a study project to demonstrate the Spring Boot ecosystem with an in-memory H2 database.

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🚀 Tech Stack

Technology	Version	Purpose
Java	17	Main language
Spring Boot	3.2.4	Core framework
Spring Data JPA	3.2.4	Data persistence
Spring Validation	3.2.4	DTO validation
H2 Database	Runtime	In-memory database
Lombok	Latest	Boilerplate reduction
JUnit 5	Latest	Unit testing
Mockito	Latest	Dependency mocking

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🏗️ Architecture

src/main/java/com/example/todoapi/
│
├── controller/          # Presentation layer — handles HTTP requests
├── service/             # Business layer — application logic and rules
│   └── impl/            # Service implementations
├── repository/          # Data layer — database communication
├── model/               # JPA entities
├── dto/                 # Data transfer objects
│   ├── TaskRequestDTO   # Input data
│   └── TaskResponseDTO  # Output data
└── exception/           # Global error handling
    ├── TaskNotFoundException
    ├── ErrorResponse
    └── GlobalExceptionHandler

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⚙️ Prerequisites

• Java 17+
• Maven 3.9+
• Git

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🔧 Getting Started

1. Clone the repository

git clone https://github.com/henriquebl/todo-api.git
cd todo-api

2. Run with Maven

./mvnw spring-boot:run

3. Or build and run the JAR

./mvnw clean package
java -jar target/todo-api-0.0.1-SNAPSHOT.jar

The application will be available at http://localhost:8080

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📡 Endpoints

Base URL: http://localhost:8080/api/tasks

Method	Endpoint	Description	Status
GET	/api/tasks	List all tasks	200 OK
GET	/api/tasks?completed=true	Filter by status	200 OK
GET	/api/tasks/{id}	Get task by ID	200 OK
POST	/api/tasks	Create a new task	201 Created
PUT	/api/tasks/{id}	Update an existing task	200 OK
DELETE	/api/tasks/{id}	Delete a task	204 No Content

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📋 Usage Examples

Create a task

POST /api/tasks
Content-Type: application/json

{
  "title": "Study Spring Boot",
  "description": "Finish the To-Do List project",
  "completed": false
}

Response 201 Created:

{
  "id": 1,
  "title": "Study Spring Boot",
  "description": "Finish the To-Do List project",
  "completed": false,
  "createdAt": "2026-03-20T02:30:00",
  "updatedAt": "2026-03-20T02:30:00"
}

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List all tasks

GET /api/tasks

Response 200 OK:

[
  {
    "id": 1,
    "title": "Study Spring Boot",
    "description": "Finish the To-Do List project",
    "completed": false,
    "createdAt": "2026-03-20T02:30:00",
    "updatedAt": "2026-03-20T02:30:00"
  }
]

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Update a task

PUT /api/tasks/1
Content-Type: application/json

{
  "title": "Study Spring Boot",
  "description": "Finish the To-Do List project",
  "completed": true
}

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Delete a task

DELETE /api/tasks/1

Response 204 No Content — no body.

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⚠️ Error Handling

Resource not found 404

{
  "status": 404,
  "message": "Task not found with id: 99",
  "timestamp": "2026-03-20T02:30:00"
}

Invalid data 400

{
  "status": 400,
  "message": "Validation error",
  "timestamp": "2026-03-20T02:30:00",
  "errors": [
    "title: Title must be between 3 and 100 characters"
  ]
}

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🗄️ Database

This project uses H2 in-memory database — data is lost when the application restarts.

Access the visual console at: http://localhost:8080/h2-console

Field	Value
JDBC URL	jdbc:h2:mem:tododb
User Name	sa
Password	(leave blank)

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🧪 Tests

# Run all tests
./mvnw test

# Run with coverage report
./mvnw test jacoco:report

Tests cover the service layer using JUnit 5 and Mockito, validating both success scenarios and exception handling.

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📁 Configuration

Located at src/main/resources/application.properties:

server.port=8080
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.show-sql=true

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🔮 Roadmap

• Authentication with Spring Security + JWT
• API documentation with Swagger / OpenAPI
• Migrate to PostgreSQL
• Pagination and sorting on list endpoints
• Deploy to Railway or Render

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👨‍💻 Author

Made by Henrique

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📄 License

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