Spring BeanDefinitionOverrideException in WebMvcAutoConfiguration for Bean requestMappingHandlerAdapter

Affects: 2.1.4.RELEASE

I'm trying to extend org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration.EnableWebMvcConfiguration which is titled as configuration equivalent to @EnableWebMvc

I need to edit this specific configuration due to a problem with request mapping in combination with feign.

But when I extend the class I get an exception: Caused by: org.springframework.beans.factory.support.BeanDefinitionOverrideException: Invalid bean definition with name 'requestMappingHandlerAdapter'

And the requestMappingHandlerAdapter is beeing overridden in WebMvcAutoConfiguration.EnableWebMvcConfiguration:

@Bean
@Override
public RequestMappingHandlerAdapter requestMappingHandlerAdapter() {
    RequestMappingHandlerAdapter adapter = super.requestMappingHandlerAdapter();
    adapter.setIgnoreDefaultModelOnRedirect(this.mvcProperties == null
            || this.mvcProperties.isIgnoreDefaultModelOnRedirect());
    return adapter;
}

which is a Bean defined in WebMvcConfigurationSupport, which is extended by DelegatingWebMvcConfiguration:

@Bean
public RequestMappingHandlerAdapter requestMappingHandlerAdapter()

A workaround would be to add the configuration spring.main.allow-bean-definition-overriding: true but i guess that this should be reported as a bug.

Comment From: snicoll

I'm trying to extend org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration.EnableWebMvcConfiguration

You shouldn't be doing that. Auto-configuration classes are not public API. I believe this wouldn't work with recent versions anyway. If you need a way to tune something, please open a request for enhancement in Spring Boot.