What is the delegating filter proxy?
It's the web servlet daemon filter proxy that delegates to a bean specified in spring.security.factories. All calls to the filter proxy that do not contain a proper route will return an error. Overview and Need for DelegatingFilterProxy in Spring
It's the servlet filter proxy delegating to a filter bean specified in web.xml. All calls to the filter proxy will be delegated to that servlet filter bean.
It's the servlet filter chain that handles requests to the route defined in spring.security.factories. All calls to the filter proxy y are forwarded to the ErrorServlet.
It's the servlet filter chain proxy that handles all requests to the route defined in spring.security.xml. All calls to the filter proxy are forwarded to the ErrorDispatcherServlet.