Why is there a cyclical addiction?

Question

Java

Good evening.
I am making a REST API based on the following tutorial
https://habr.com/en/post/482552/

And for some reason a cyclic dependency appeared
Specifically, this moment was made exactly as in the article


I tried to add the Lazy annotation, it gives an error


Here is a link to the git,
Help please sort out the reasons
https://gitlab.com/alkella99/notes_api/-/tree/master

Answer 1

@Configuration
public class AppConfig {

    @Autowired
    @Lazy
    UserService userService;

    @Bean
    public BCryptPasswordEncoder bCryptPasswordEncoder() {
        return new BCryptPasswordEncoder(5);
    }

    @Autowired
    protected void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userService).passwordEncoder(bCryptPasswordEncoder());
    }
}

@Configuration is not a bean, not a service. You don't need to autowire anything there.

@Autowired
    protected void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userService).passwordEncoder(bCryptPasswordEncoder());
    }

- there is some kind of abracadabra here. What does void do in config? Why is he throwing an exception?
If you need to perform some actions after the bean is built, think about the @PostConstruct annotation.
You can try, for example, add to the UserService:

...
    @Autowired
    AuthenticationManagerBuilder auth;

  @PostConstruct
    void init() {
        auth.userDetailsService(this).passwordEncoder(bCryptPasswordEncoder);
    }
...

Answer 2

I solved it all by specifying in application.properties:
spring.main.allow-circular-references: true