How to do it...

1. It is a good idea to separate and group the configurations into different classes in order to provide more clarity about what kind of things are being configured. So, let's create a separate configuration class called WebConfiguration in the src/main/java/com/example/bookpub directory from the root of our project with the following content:

@Configuration 
public class WebConfiguration { 
    @Bean 
    public RemoteIpFilter remoteIpFilter() { 
        return new RemoteIpFilter(); 
    } 
} 

1. Start the application by running ./gradlew clean bootRun.
2. In the startup log, we should see the following line, indicating that our filter has been added:

...FilterRegistrationBean : Mapping filter: 'remoteIpFilter' to: [/*]