Prevent Spring Boot from registering a servlet filter

I have a Spring Boot WebMVC application, and a bean that inherits from AbstractPreAuthenticatedProcessingFilter which I am explicitly adding to a specific spot in the Spring Security filter chain. My Spring Security configuration looks like this:

<http pattern="/rest/**">
  <intercept-url pattern="/**" access="ROLE_USER"/>
  <http-basic/>
  <custom-filter after="BASIC_AUTH_FILTER" ref="preAuthenticationFilter"/>
</http>

<beans:bean id="preAuthenticationFilter" class="a.b.PreAuthenticationFilter">
  <beans:property name="authenticationManager" ref="customAuthenticationManager"/>
</beans:bean>

The security configuration works. The problem is, because the PreAuthenticationFilter class inherits from AbstractPreAuthenticatedProcessingFilter, Spring Boot treats it as a general purpose servlet filter and is adding it to the servlet filter chain for all requests. I don't want this filter to be part of the filter chain for all requests. I only want it to be part of the specific Spring Security filter chain that I've configured. Is there a way to prevent Spring Boot from automatically adding the preAuthenticationFilter bean to the filter chain?

Solution 1:

By default Spring Boot creates a FilterRegistrationBean for every Filter in the application context for which a FilterRegistrationBean doesn't already exist. This allows you to take control of the registration process, including disabling registration, by declaring your own FilterRegistrationBean for the Filter. For your PreAuthenticationFilter the required configuration would look like this:

@Bean
public FilterRegistrationBean registration(PreAuthenticationFilter filter) {
    FilterRegistrationBean registration = new FilterRegistrationBean(filter);
    registration.setEnabled(false);
    return registration;
}

You may also be interested in this Spring Boot issue which discusses how to disable the automatic registration of Filter and Servlet beans.

Solution 2:

If you want to unregister all filters at one time here's my trick:

public class DefaultFiltersBeanFactoryPostProcessor implements BeanFactoryPostProcessor {

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory bf)
            throws BeansException {
        DefaultListableBeanFactory beanFactory = (DefaultListableBeanFactory) bf;

        Arrays.stream(beanFactory.getBeanNamesForType(javax.servlet.Filter.class))
                .forEach(name -> {

                    BeanDefinition definition = BeanDefinitionBuilder
                            .genericBeanDefinition(FilterRegistrationBean.class)
                            .setScope(BeanDefinition.SCOPE_SINGLETON)
                            .addConstructorArgReference(name)
                            .addConstructorArgValue(new ServletRegistrationBean[]{})
                            .addPropertyValue("enabled", false)
                            .getBeanDefinition();

                    beanFactory.registerBeanDefinition(name + "FilterRegistrationBean",
                            definition);
                });
    }
}

A bit more about this technique - here.

Solution 3:

If you need to disable registering 2 filters(like i did), include a name for the bean(so that they do not override):

@Bean(name = "filterRegistrationBean1")
public FilterRegistrationBean<YourFilter1> registration(YourFilter1 f1) {
    FilterRegistrationBean<YourFilter1> registration = new FilterRegistrationBean<>(f1);
    registration.setEnabled(false);
    return registration;
}

@Bean(name = "filterRegistrationBean2")
public FilterRegistrationBean<YourFilter2> registration(YourFilter2 f2) {
    FilterRegistrationBean<YourFilter2> registration = new FilterRegistrationBean<>(f2);
    registration.setEnabled(false);
    return registration;
}