Authentication Server with spring, JWT & JPA

  1. Create a Spring Boot Project:

  2. Use Spring Initializr to create a new project with dependencies for Spring Web, Spring Security, Spring Data JPA, and H2 Database.

  3. Configure Database:

  4. Set up database properties in application.properties or application.yml.

  5. Configure an Entity class for the user and any other necessary entities.

  6. UserDetailsService Implementation:

  7. Create a class implementing the UserDetailsService interface.

  8. Override the loadUserByUsername method to load user details from the database.

  9. User Entity:

  10. Annotate the user entity with @Entity and include necessary fields like username, password, and roles.

  11. Use @OneToMany and @ManyToMany annotations for relationships, if needed.

  12. Repository Interface:

  13. Create a repository interface extending JpaRepository for the user entity.

  14. Implement custom query methods if required.

  15. Security Configuration:

  16. Create a class extending WebSecurityConfigurerAdapter.

  17. Override the configure method to set up authentication using the UserDetailsService and configure password encoding.

  18. Generate JWT Token:

  19. Create a class to generate JWT tokens.

  20. Use a library like jjwt to build and sign the token with a secret key.

  21. Authentication Controller:

  22. Create a controller class for handling authentication requests.
  23. Expose an endpoint for user login.

  24. Authenticate the user using AuthenticationManager and generate a JWT token.

  25. Token Validation Filter:

  26. Create a filter to validate JWT tokens on incoming requests.

  27. Extract the token from the Authorization header and validate it using the secret key.

  28. Security Configuration Update:

    • Update the security configuration to include the JWT token validation filter.

  29. Token Refresh Endpoint (Optional):

    • Create an endpoint for refreshing the JWT token.
    • Validate the old token and generate a new one with an extended expiration time.

  30. Testing:

    • Write unit and integration tests for the authentication process, including successful login and token validation.