Spring Security using JWT

Spring Boot Security with JWT (Hands-On)

What you’ll learn

Spring Security fundamentals

JWT Access & Refresh Tokens

Login / Signup APIs

Role-based authorization

Token validation & filters

Best for: Beginners → Intermediate

Why it’s good: Very practical, lots of REST API examples

What is JWT

JWT (JSON Web Token) is a small, compact token used to securely identify a user in web applications.

It is mainly used for authentication and authorization in REST APIs.

A JWT has three parts:
Header – contains token type and algorithm
Payload – contains user information and expiry time
Signature – ensures the token is not modified

How it works:
The user logs in with username and password.
The server generates a JWT and sends it to the client.
The client sends this token with every request.
The server verifies the token and allows access.

JWT is stateless, meaning the server does not store session data.

It is fast, scalable, and commonly used in microservices.

JWT is signed, not encrypted, so sensitive data should not be stored in it.

HTTPS should always be used with JWT.