[keycloak-user] Spring Security Adapter & Filter Bean Registration

[Kuestermann, Thomas]

Keycloak experts,

We've got a working Spring Boot application that integrates with Keycloak via Spring Security adapter. Works great so far! I read the documentation (http://www.keycloak.org/docs/3.3/securing_apps/topics/oidc/java/spring-security-adapter.html), section "Avoid double Filter bean registration", and it states that "it may be necessary to add two FilterRegistrationBeans to your security configuration to prevent the Keycloak filters from being registered twice".

Under which circumstances do we need to add the mentioned FilterRegistrationBeans to the configuration as I cannot see filters from being registered twice? Blindly adding the filters results in no filter to be applied at all. 

I'd like to be clear about this as I'm relatively new to the technology involved.

Thanks for shedding some light on it!

-- Thomas