If we want to override Spring Boot's default configuration or if we want to add our own configuration, we can simply annotate a class with @Configuration and it will be picked up by the component scanning mechanism we described previously.

For example, if we want to set up a filter in the processing of HTTP requests (handled by Spring WebFlux, which is described in the following section) that writes a log message at the beginning and the end of the processing, we can configure a log filter, as follows: