How do I manually register filters in springboot?

Question

I have three Filter class: AFilter、BFilter、CFilter，and attempt to register them by the following code:

@Component
public class DefaultFilterRegister implements BeanDefinitionRegistryPostProcessor {

    //......

    private List<Filter> toRegister = FilterUtils.getInitFilters();

    @Override
    public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
        if (CollectionUtils.isEmpty(toRegister)) {
            return;
        }
        for (Filter filter : toRegister) {

            BeanDefinitionBuilder beanDefinitionBuilder =
                    BeanDefinitionBuilder.genericBeanDefinition(filter.getClass());

            AbstractBeanDefinition rawBeanDefinition = beanDefinitionBuilder.getRawBeanDefinition();

            rawBeanDefinition.setAutowireMode(GenericBeanDefinition.AUTOWIRE_BY_TYPE);

            registry.registerBeanDefinition(filter.getClass().getName(), rawBeanDefinition);
        }
    }

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {

    }
    
    //......

}

They had been register to beanfactory, but they are not filters. How can I turn them into filters?

My main goal is to make the built-in filters and user-defined filters orderable. Using the above example of AFilter, BFilter, and CFilter, these three are system built-in, and when the user wants to add a DFilter, I can provide something like addFilterBefore() to make the filter order A, D, B, C.

Answer 1

You can return the below bean in your web security configuration to register the filter. Like below example.

@Bean 
public FilterRegistrationBean<CustomFilter> restRegistrationBean() {   
      FilterRegistrationBean<CustomFilter> filterRegistrationBean = new FilterRegistrationBean<>();
      filterRegistrationBean.setFilter(customFilterObject);
      filterRegistrationBean.addUrlPatterns("/mapping1","/mapping2"); 
      return filterRegistrationBean; 
}