My Note API

A Spring Boot RESTful API for a personal note-taking application with JWT authentication, built with Kotlin, Spring Data JPA, PostgreSQL, Flyway, Spring Security, and JJWT.

Features

• Authentication & Authorization

  • JWT-based authentication with secure token generation
  • User registration and login
  • Token-based API access control

• Notes Management

  • Create, read, update, and delete personal notes
  • Pin important notes
  • Filter notes by category
  • Full audit trail (createdAt, updatedAt)

• Categories

  • Organize notes with custom categories
  • Color-coded categories for visual organization
  • CRUD operations for category management
  • Category names are trimmed and unique per user, case-insensitively (Work and work are considered duplicates)

• Security

  • Spring Security with JWT tokens
  • Password encryption with BCrypt
  • User-scoped data isolation (users can only access their own data)

Project Structure

my-note/
├── src/main/kotlin/com/yoesuv/mynote/
│   ├── config/          # Configuration classes (Security, JPA, JWT)
│   ├── controller/      # REST API controllers
│   ├── domain/          # JPA entities
│   ├── dto/             # Data Transfer Objects
│   │   ├── auth/        # Auth request/response DTOs
│   │   ├── category/    # Category request/response DTOs
│   │   └── note/        # Note request/response DTOs
│   ├── exception/       # Exception handling
│   ├── repository/      # Spring Data repositories
│   ├── security/        # JWT service and filters
│   └── service/         # Business logic layer
├── src/main/resources/
│   └── db/migration/    # Flyway database migrations
└── docs/                # API documentation

System Flow

flowchart TD
    user["User"] --> app["Client app or API tool"]
    app --> auth{"Has an account?"}

    auth -->|"No"| register["Register"]
    auth -->|"Yes"| login["Login"]

    register --> token["Receive access token"]
    login --> token

    token --> actions["Use My Note API"]

    actions --> notes["Create, view, update, and delete notes"]
    actions --> categories["Create, view, update, and delete categories"]
    categories --> categoryRules["Validate category name: trim spaces and reject case-insensitive duplicates per user"]
    actions --> logout["Logout"]

    notes --> database["PostgreSQL database"]
    categoryRules --> database
    logout --> finished["Session finished on client"]

    database --> saved["User data is stored separately and securely"]

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Getting Started

Prerequisites

• Java 17 or higher
• PostgreSQL 12+
• Gradle is optional because this project includes the Gradle wrapper (./gradlew)

Setup

1. Clone the repository

   git clone <repository-url>
   cd my-note

2. Create database

   Create a PostgreSQL database. Flyway will create the schema and tables when the application starts.

   CREATE DATABASE mynotes;

   Or using psql:

   psql -U your_username -c "CREATE DATABASE mynotes;"

3. Configure database connection

   Create a local configuration file named local.properties in the project root. This file is ignored by Git and is automatically imported by the application.

   DB_URL=jdbc:postgresql://localhost:5432/mynotes
   DB_USERNAME=your_username
   DB_PASSWORD=your_password

   If your PostgreSQL user does not use a password, leave it empty:

   DB_PASSWORD=

4. Configure JWT (optional)

   Add JWT settings to local.properties if you want to override the defaults:

   JWT_SECRET=your-256-bit-secret-key-here-minimum-32-characters

5. Run the application

   ./gradlew bootRun

   To run with development seed data, use the dev profile:

   ./gradlew bootRun --args='--spring.profiles.active=dev'

   The dev profile seeds demo users, categories, and notes if they do not already exist:

   Email	Password
   demo@mynotes.com	password
   john@example.com	password

   Or build and run the JAR:

   ./gradlew build
   java -jar build/libs/my-note-0.0.1-SNAPSHOT.jar

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

API Documentation

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

Resource	Endpoints
Auth	POST /auth/register, POST /auth/login, POST /auth/logout
Notes	GET/POST /notes, GET/PUT/DELETE /notes/{id}
Categories	GET/POST /categories, GET/PUT/DELETE /categories/{id}

All endpoints except /auth/** require Authorization: Bearer <token> header.

For full documentation with request/response examples and error codes, see:

• Register API
• Login API
• Notes API
• Categories API

Database Schema

The application uses Flyway for database migrations. Tables are automatically created:

• users - User accounts
• categories - Note categories
• notes - User notes

Running Tests

./gradlew test

Building for Production

./gradlew bootJar

The production JAR will be in build/libs/.

License

This project is open source and available under the MIT License.

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Note: This is a backend API. For a complete application, pair it with a frontend client (web, mobile, or desktop).