🚀 Spring Boot JWT Authentication & Authorization REST API

Secure Authentication using Spring Security | JWT | BCrypt | MySQL | Flyway

A production-ready RESTful API implementing secure JWT Authentication & Authorization using Spring Security, BCrypt password encryption, MySQL, Hibernate ORM, and Flyway database migrations.

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📌 Project Overview

This project was developed as part of the Prodigy InfoTech Internship – Task 3: JWT Authentication & Authorization.

The application extends the previous CRUD REST API by integrating Spring Security and JSON Web Tokens (JWT) to secure all protected endpoints.

Users can register, securely log in, receive a JWT access token, and access protected APIs only after successful authentication. Passwords are encrypted using BCrypt before being stored in the MySQL database.

The project follows Spring Boot best practices with a layered architecture, making it scalable and production-ready.

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✨ Features

• ✅ User Registration
• ✅ User Login
• ✅ JWT Authentication
• ✅ Spring Security Integration
• ✅ BCrypt Password Encryption
• ✅ Stateless Authentication
• ✅ Protected REST APIs
• ✅ User CRUD Operations
• ✅ Spring Data JPA
• ✅ Hibernate ORM
• ✅ MySQL Integration
• ✅ Flyway Database Migration
• ✅ DTO Validation
• ✅ Global Exception Handling
• ✅ UUID Primary Keys
• ✅ Password Hidden from API Responses

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🛠 Tech Stack

Technology	Purpose
Java 21	Programming Language
Spring Boot	Backend Framework
Spring Security	Authentication & Authorization
JWT	Token-Based Authentication
Spring Data JPA	Data Access Layer
Hibernate	ORM Framework
MySQL	Relational Database
Flyway	Database Migration
BCrypt	Password Encryption
Maven	Dependency Management
Postman	API Testing
IntelliJ IDEA	Development Environment

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🏗 Project Architecture

                    Client (Postman)
                           │
                           ▼
                 Authentication Controller
                           │
                           ▼
                Authentication Service
                           │
                           ▼
                BCrypt Password Encoder
                           │
                           ▼
                  User Repository (JPA)
                           │
                           ▼
                    Hibernate ORM Layer
                           │
                           ▼
                     MySQL Database
                           ▲
                           │
                 JWT Authentication Filter
                           │
                           ▼
                  Protected REST APIs

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📂 Project Structure

basic-rest-api
│
├── src
│   ├── main
│   │   ├── java
│   │   │   └── com.example.basic_rest_api
│   │   │
│   │   ├── config
│   │   ├── controller
│   │   ├── dto
│   │   ├── exception
│   │   ├── model
│   │   ├── repository
│   │   ├── security
│   │   ├── service
│   │   └── BasicRestApiApplication
│   │
│   │   └── resources
│   │       ├── application.properties
│   │       └── db
│   │           └── migration
│
├── pom.xml
├── README.md
└── .gitignore

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🔐 JWT Authentication Flow

              Register User
                    │
                    ▼
      Password Encrypted using BCrypt
                    │
                    ▼
          Stored in MySQL Database
                    │
                    ▼
               User Login
                    │
                    ▼
          Credentials Verified
                    │
                    ▼
            JWT Token Generated
                    │
                    ▼
      Authorization: Bearer <TOKEN>
                    │
                    ▼
      JWT Authentication Filter
                    │
                    ▼
      Access Protected REST APIs

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🗄 Database Details

Property	Value
Database	MySQL
ORM	Hibernate
Repository	Spring Data JPA
Migration Tool	Flyway
Password Encryption	BCrypt
Primary Key	UUID

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🔗 REST API Endpoints

Authentication APIs

Method	Endpoint	Description
POST	/auth/register	Register User
POST	/auth/login	Login User

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Protected User APIs

Method	Endpoint	Description
GET	/api/users	Retrieve All Users
GET	/api/users/{id}	Retrieve User by ID
POST	/api/users	Create User
PUT	/api/users/{id}	Update User
DELETE	/api/users/{id}	Delete User

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🧪 Sample API Requests

Register User

POST /auth/register

{
  "name": "John Doe",
  "email": "john@example.com",
  "age": 24,
  "password": "password123"
}

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Login

POST /auth/login

{
  "email": "john@example.com",
  "password": "password123"
}

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Login Response

{
  "token": "eyJhbGciOiJIUzI1NiJ9..."
}

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Access Protected Endpoint

GET /api/users

Header:

Authorization: Bearer <JWT_TOKEN>

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⚙️ How to Run the Project

Clone Repository

git clone https://github.com/uddishasinghh31/YOUR_REPOSITORY_NAME.git

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Configure MySQL

CREATE DATABASE prodigy_task3_db;

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Update application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/prodigy_task3_db
spring.datasource.username=YOUR_USERNAME
spring.datasource.password=YOUR_PASSWORD

jwt.secret=YOUR_SECRET_KEY
jwt.expiration=86400000

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Run the Project

mvn spring-boot:run

Or run:

BasicRestApiApplication.java

The application will start on:

http://localhost:8080

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🔒 Security Features

• BCrypt Password Encryption
• JWT Authentication
• Stateless Session Management
• Spring Security Integration
• JWT Authentication Filter
• Protected Endpoints
• Secure Password Storage
• UUID-Based Primary Keys
• DTO Validation
• Global Exception Handling

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🚀 Future Improvements

• Refresh Token Support
• Role-Based Authorization (Admin/User)
• Swagger / OpenAPI Documentation
• Docker Containerization
• Unit & Integration Testing
• GitHub Actions CI/CD
• Cloud Deployment (AWS / Railway / Render)

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👩‍💻 Author

Udisha Singh

Backend Developer | Java | Spring Boot | MySQL

Linkedin: https://www.linkedin.com/in/udisha-singh-47170b338

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📄 Internship Details

Organization: Prodigy InfoTech

• Task 1: Build a REST API for CRUD Operations
• Task 2: Integrate Persistent Storage using MySQL, Spring Data JPA, Hibernate, and Flyway
• Task 3: Implement JWT-Based Authentication & Authorization using Spring Security and JSON Web Tokens

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