intermediateSpring Security
What is UserDetailsService? How does Spring Security authenticate a user?
UsernamePasswordAuthenticationFilter extracts credentials, builds a token, and passes it to AuthenticationManager, which delegates to DaoAuthenticationProvider — that calls UserDetailsService.loadUserByUsername(), compares the password via PasswordEncoder.matches(), and on success sets the resulting Authentication into SecurityContext.
Ready to master this question?
Generate a complete walkthrough — background, the full answer in plain language, a working code example explained line by line, a real-world scenario, common mistakes, and how this same question gets asked in different ways.
Sign in to generate a response