Task Manager API

A Spring Boot REST API for managing users and tasks.

This project was built as a practical backend project for Java and Spring Boot interview preparation.

Features

• User CRUD
• Task CRUD
• User and Task relationship
• Request DTOs
• Response DTOs
• Mapper classes
• Validation
• Global Exception Handling
• Duplicate email handling
• Not Found handling
• Pagination and Sorting
• Filter tasks by status
• Transaction management with @Transactional
• H2 in-memory database

Technologies

• Java 21
• Spring Boot
• Spring Web
• Spring Data JPA
• Hibernate
• H2 Database
• Bean Validation
• Lombok
• Maven
• Git
• GitHub

Project Structure

controller -> REST API endpoints

service -> Business logic

repository -> Database access

entity -> JPA entities

dto -> Request and response objects

mapper -> Converts Entity to DTO

exception -> Global error handling

User APIs

POST /api/users

Create a new user.

GET /api/users

Get all users.

GET /api/users/{id}

Get user by id.

PUT /api/users/{id}

Update user.

DELETE /api/users/{id}

Delete user.

Task APIs

POST /api/tasks/users/{userId}

Create a new task for a user.

GET /api/tasks

Get all tasks.

GET /api/tasks/{id}

Get task by id.

PUT /api/tasks/{id}

Update task.

DELETE /api/tasks/{id}

Delete task.

GET /api/tasks/users/{userId}

Get all tasks for a specific user.

GET /api/tasks/status/{status}

Filter tasks by status.

GET /api/tasks/paged

Get tasks with pagination and sorting.

Example User Request

{
  "name": "Minoo",
  "email": "minoo@test.com"
}

Example Task Request

{
  "title": "Learn Spring Boot",
  "description": "Practice backend project",
  "status": "TODO",
  "dueDate": "2026-06-10"
}

Task Status Values

TODO

IN_PROGRESS

DONE

H2 Console

The project uses H2 in-memory database.

H2 Console URL:

http://localhost:8080/h2-console

JDBC URL:

jdbc:h2:mem:task_manager_db

Username:

sa

Password:

empty

Run Project

mvn spring-boot:run

The app runs on:

http://localhost:8080

Pagination Example

GET /api/tasks/paged?page=0&size=5&sortBy=dueDate&direction=asc

What I Practiced

• Layered architecture in Spring Boot
• REST API design
• JPA relationships
• DTO and Mapper pattern
• Validation and exception handling
• Transaction management
• Git and GitHub workflow

Future Improvements

• Add JWT authentication and authorization
• Add user login and registration
• Replace H2 database with PostgreSQL or MySQL
• Add unit tests for service layer
• Add integration tests for API endpoints
• Add Docker support
• Add Swagger/OpenAPI documentation