JwtUtil

Info

@Component for JWT token generation, parsing, and validation using HMAC-SHA signing via the JJWT library.

Overview

Provides JWT operations for the authentication subsystem. Generates tokens with username (subject) and role claims, parses claims from tokens, and validates token integrity and expiry. Uses HMAC-SHA key derived from a configurable secret.

Key Methods

Method	Description	Returns
generateToken(username)	Generate JWT with default "user" role	String token
generateToken(username, role)	Generate JWT with specified role	String token
getUsernameFromToken(token)	Extract username (subject) from token	String
getRoleFromToken(token)	Extract role claim (defaults to "user")	String
validateToken(token)	Check if token is valid (signature + expiry)	boolean

Token Claims

Claim	Type	Description
sub	String	Username (subject)
role	String	User role (e.g. "user", "admin")
iat	Date	Issued at timestamp
exp	Date	Expiration timestamp

Configuration Properties

Property	Env / YAML Key	Default	Description
Secret	jwt.secret	(required)	HMAC signing key
Expiration	jwt.expiration	(required)	Token TTL in milliseconds

Dependencies

• JJWT library (io.jsonwebtoken)