Spring Security 5 + OAuth2 + Webflux : authorization success listeners

Question

In 'Spring Security Reference' page, section 5.11 Post Processing Configured Objects introduces the concept of an ObjectPostProcessor where we can configure a filterSecurityPublishAuthorizationSuccess property on FilterSecurityInterceptor.

@EnableWebSecurity
public class ResourceServerConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .anyRequest().authenticated()
                .withObjectPostProcessor(new ObjectPostProcessor<FilterSecurityInterceptor>() {
                    public <O extends FilterSecurityInterceptor> O postProcess(O fsi) {
                        fsi.setPublishAuthorizationSuccess(true); //1 This requires JavaX Servlet API
                        return fsi;
                    }
                });
    . . . 
}

In my case using this ObjectPostProcessor I'm able to log authorization success using an ApplicationListener.

package org.mycompany.security.reactive.logging;

    public class AuthorizationSuccessListener implements ApplicationListener<AuthorizedEvent> {
        @Override
        public void onApplicationEvent(AuthorizedEvent event) {
        
            // log journals
        
        }
    }
    . . .

Right now I'm migrating my application to use Spring Webflux (Reactive) instead of RestTemplate (Java Servlet API).

The problem after migrating my code is: the code from Spring Security page requires the Servlet API (error: The type javax.servlet.Filter cannot be resolved. ) on the line with my comment: //1.

The client code is a simple @RestController + @GetMapping using Spring WebClient.

Has anyone been through a situation like this or know another approach?