Package me.josephsf.jobportaljosephsfeir.security

Class JwtUtils

java.lang.Object
me.josephsf.jobportaljosephsfeir.security.JwtUtils
@Component public class JwtUtils extends Object
Utility class for handling JWT (JSON Web Token) operations.

This component provides functionality for JWT token generation, validation, and parsing. It uses the JJWT library to create and verify JSON Web Tokens used for authentication and authorization throughout the application. The tokens are signed with HMAC-SHA512 for security.

Key capabilities include:

  • Token generation for authenticated users
  • Token validation to verify integrity and expiration
  • Extraction of username from tokens for authentication
  • Configurable secret key and token expiration time

This class is configured via properties that can be set in application.properties:

  • jobportal.app.jwtSecret - The secret key used for signing tokens
  • jobportal.app.jwtExpirationMs - The token validity period in milliseconds
Since:
2025-05-15

  • Constructor Details

    • JwtUtils

      public JwtUtils()
      Constructs a new JwtUtils instance.

      Default constructor that allows Spring to initialize this component and inject the necessary property values from the application configuration.

  • Method Details

    • generateJwtToken

      public String generateJwtToken(String username)
      Generates a JWT token for a user.

      Creates a new signed token containing the username as subject, issue time, and expiration time. The token is signed with HMAC-SHA512 using the configured secret key.

      Parameters:
      username - the username to include in the token
      Returns:
      the JWT token string

    • getUserNameFromJwtToken

      public String getUserNameFromJwtToken(String token)
      Extracts the username from a JWT token.

      Parses the token, verifies its signature using the signing key, and extracts the subject claim which contains the username.

      Parameters:
      token - the JWT token string
      Returns:
      the username from the token
      Throws:
      io.jsonwebtoken.JwtException - if the token is invalid or cannot be parsed

    • validateJwtToken

      public boolean validateJwtToken(String authToken)
      Validates a JWT token.

      Checks if the token is well-formed, has a valid signature, and has not expired. Logs specific errors to help with debugging.

      Parameters:
      authToken - the JWT token string to validate
      Returns:
      true if the token is valid, false otherwise