Learn Spring Boot Todo API (AKA Todo API)

A simple Spring Boot REST API for a Todo service, following a layered architecture (Controller → Service → Repository) with DTOs, validation, and an H2 in-memory database.

Built in VS Code using the Spring Boot Development Pack (Spring Initializr, Boot Dashboard, run/debug). https://marketplace.visualstudio.com/items?itemName=vmware.vscode-boot-dev-pack

Tech Stack

Java 17 • Spring Boot 3 • Spring Web • Spring Data JPA • Jakarta Validation • Jackson • H2 (in-memory) • Maven

Run

CLI (Maven)

./mvnw spring-boot:run

VS Code (Dev Pack)

1. Open the project folder in VS Code.
2. Open the Spring Boot Dashboard (left sidebar).
3. Click Run on the app to start with live reload/debug.

H2 Console

• URL: http://localhost:8080/h2-console
• JDBC URL: jdbc:h2:mem:todo
• Username: sa • Password: (blank)

API Endpoints

Method	Path	Description
POST	/api/todos	Create a todo
GET	/api/todos	List todos (?completed=true)
GET	/api/todos/{id}	Get by id
PATCH	/api/todos/{id}	Partial update
DELETE	/api/todos/{id}	Delete

Example

curl -X POST http://localhost:8080/api/todos \
  -H "Content-Type: application/json" \
  -d '{"title":"Learn Spring Boot","dueDate":"2025-10-01"}'

curl "http://localhost:8080/api/todos?completed=false"

Project Structure

src/main/java/com/example/tasksmanager
└─ TasksmanagerApplication.java          # @SpringBootApplication (root)
└─ todo/
   ├─ domain/
   │  └─ Todo.java                       # entity/domain
   ├─ repo/
   │  └─ TodoRepository.java             # data access (Spring Data JPA)
   ├─ service/
   │  ├─ TodoService.java                # business logic + transactions
   │  └─ TodoNotFoundException.java      # domain/app error
   ├─ dto/
   │  ├─ CreateTodoRequest.java          # DTO (request)
   │  ├─ UpdateTodoRequest.java          # DTO (request)
   │  └─ TodoResponse.java               # DTO (response)
   ├─ mapper/
   │  └─ TodoMapper.java                 # entity ↔ DTO conversion
   └─ web/
      └─ TodoController.java             # HTTP API

How it was built (timeline)

1. Generated a Spring Boot app (Java 17, Maven) with Spring Web, Spring Data JPA, Validation, and H2 using the VS Code Spring Boot Development Pack (Initializr).
2. Created the Todo entity, a Spring Data repository, and a service with CRUD + filtering and transactions.
3. Exposed REST endpoints via a thin controller, using DTOs and a small mapper for entity↔DTO conversion (Jackson handles JSON↔DTO).
4. Configured H2 in-memory DB and enabled the H2 console.
5. Verified endpoints with curl (no tests in this repo).