Spring Boot and JWT

A simple Spring Boot application demonstrating JWT (JSON Web Token) authentication using Aspect-Oriented Programming (AOP).

Overview

This project showcases how to implement JWT-based authentication in a Spring Boot application using AOP. The application intercepts all REST controller method calls and validates the JWT token provided in the request header.

Technologies Used

• Java 21
• Spring Boot 3.2.10
• Spring AOP
• JJWT (JSON Web Token for Java) 0.11.5
• JUnit 5 for testing
• Maven for dependency management

Features

• JWT token generation and validation
• AOP-based authentication for all REST endpoints
• Simple Hello World REST API

Prerequisites

• Java 21 or higher
• Maven 3.6 or higher

Getting Started

Clone the Repository

git clone https://github.com/edwin/spring-boot-and-jwt.git
cd spring-boot-and-jwt

Build the Project

mvn clean install

Run the Application

mvn spring-boot:run

The application will start on port 8080 by default.

API Endpoints

Hello World Endpoint

GET /

Returns a simple "Hello World!" message in JSON format.

Example response:

{
  "message": "Hello World!"
}

Note: All endpoints require a valid JWT token in the request header.

Authentication

All REST endpoints in this application are protected by JWT authentication. To access any endpoint, you need to include a valid JWT token in the request header.

JWT Token Header

Include the JWT token in the my_token header of your HTTP request:

my_token: <your_jwt_token>

JWT Token Format

The JWT token contains the following claims:

• Subject: Username
• Custom claim "username": Username
• Issued At: Token creation time
• Expiration: Token expiration time (1 hour after creation by default)

Token Expiration

• Access tokens expire after 1 hour (3600000 milliseconds)
• Refresh tokens expire after 24 hours (86400000 milliseconds)

Testing

Run the tests using Maven:

mvn test

The project includes comprehensive tests for JWT token generation and validation.

Test Classes

JwtUtilsTest

Located in src/test/java/com/edw/JwtUtilsTest.java, this test class verifies the functionality of the JWT utility class:

• Token Generation: Tests that tokens are correctly generated with proper claims
• Token Validation: Validates that the system correctly identifies:
  • Valid tokens
  • Invalid/malformed tokens
  • Empty tokens
  • Expired tokens

HelloWorldControllerTest

Located in src/test/java/com/edw/controller/HelloWorldControllerTest.java, this test class verifies the REST API functionality:

• Authentication Testing: Verifies that accessing the endpoint without a JWT token returns HTTP 500
• Endpoint Functionality: Confirms that accessing the endpoint with a valid JWT token returns HTTP 200 and the correct "Hello World!" message

Configuration

The application configuration is in src/main/resources/application.properties:

spring.application.name=spring-boot-and-jwt
server.port=8080

# logging
logging.level.root=INFO
logging.level.com.edw=DEBUG

Author

Muhammad Edwin