Referencing a @Bean method in a @Configuration class' @PostConstruct method leads to circular reference

After upgrading to spring-boot 2.6.x, it is no longer possible to access a bean in the @PostConstruct method of the @Configuration class where it was defined. This did work before (tested with 2.1.x, 2.5.6).

Example code that will result in a BeanCurrentlyInCreationException, printing “Application Failed to start”, with “The dependencies of some of the beans in the application context form a cycle:”

@Configuration
public class AppConf {

    @Bean
    public String getTestBean() {
        return "";
    }

    @PostConstruct
    public void init() {
        getTestBean();
    }

}

You can get a full example at https://github.com/BartRobeyns/boot26ConfigPostConstruct (spring-initializer project with only the @Configuration class above added) that fails to build.

Changing the spring-boot version to 2.5.x will allow the application to build and run.

Note that I’m totally fine with this behavior (@PostConstruct in a @Configuration class seems pretty weird to me), but the documentation of @PostConstruct does state that the

The PostConstruct annotation is used on a method that needs to be executed after dependency injection is done to perform any initialization. This annotation must be supported on all classes that support dependency injection.

… so it’s easy to expect the sample above to work. An explicit mention that you shouldn’t access @Bean methods from the @Configuration class itself would clear that up.

[BartRobeyns]

@snicoll that clarifies the release notes for me, thanks. I still think that an extra warning in the documentation that you shouldn’t access @Bean methods from the @Configuration class itself would help users that are puzzled by the circular reference error mentioning only the @Configuration class; it’s difficult for a user to understand how that @Configuration class can have an invalid circular reference to itself. (But feel free to close this ticket without further action if you disagree)

[rstoyanchev]

Added to triage queue as there is some change in behavior, possibly requiring a small documentation update/clarification?