I was following a tutorial on YouTube on SpringSecurity and ran into the following error:

DESCRIPTION:

Parameter 0 of constructor in com.example.demo.controllers.AuthenticationController required a bean of type ‘org.springframework.security.authentication.AuthenticationManager’ that could not be found.

ACTION:

Consider defining a bean of type ‘org.springframework.security.authentication.AuthenticationManager’ in your configuration.

But I’ve already declared a bean in the SecurityConfig class, as shown below. As for public default contructor, I used @RequiredArgsConstructor annotation from Lombok. I can’t see why it should still give me the same error.

AuthenticationController.java

package com.example.demo.controllers;

@RestController
@RequestMapping("/api/v1/auth")
@RequiredArgsConstructor
public class AuthenticationController {

    private final AuthenticationManager authenticationManager;
    private final UserDao userDao;
    private final JwtUtils jwtUtils;

    @PostMapping("/authenticate")
    public ResponseEntity<String> authenticate(
        @RequestBody AuthenticationRequest request
    ) {
        authenticationManager.authenticate(
            new UsernamePasswordAuthenticationToken(request.getEmail(), request.getPassword())
        );
        ...
    }
}

SecurityConfig.java

package com.example.demo.config;

@EnableWebSecurity
@RequiredArgsConstructor
public class SecurityConfig {
    ...

    @Bean
    public AuthenticationManager authenticationManager(
            AuthenticationConfiguration config) throws Exception {
        return config.getAuthenticationManager();
    }

    ...
}