Interceptor for not existing request mapping with java configuration

Question

I have a configuration class, which extends WebMvcConfigurationSupport and I have added interceptors like this:

@Override
public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(myInterceptor()).addPathPatterns("/api/**");
}

where myInterceptor() is:

@Bean
public MyInterceptor myInterceptor() {
    return new MyInterceptor();
}

and it works fine for any mapping (/api/**) which I have implemented for example /api/sample - preHandle from MyInterceptor is fired (I have a Controller with mapping /api/sample).

When I call not existing resource for example /api/forward/sample preHandle from MyInterceptor is never called.

Please notice it worked as expected when I had the config in xml, like:

<mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/api/**" />
        <bean class="my.pack.MyInterceptor" />
    </mvc:interceptor>
</mvc:interceptors>

For some reason with java configuration requests for not existing mappings are not intercepted. Why the configuration is not equivalent? I thought it should be.

EDIT:

A bit more debugging information. With xml configuration DispatcherServlet#handlerMappings contains 5 handlers:

org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping
org.springframework.web.socket.server.support.WebSocketHandlerMapping
org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping
org.springframework.security.oauth2.provider.endpoint.FrameworkEndpointHandlerMapping
org.springframework.web.servlet.handler.SimpleUrlHandlerMapping

with Java configuration it contains 7 handlers:

org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping
org.springframework.web.socket.server.support.WebSocketHandlerMapping
org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping
org.springframework.security.oauth2.provider.endpoint.FrameworkEndpointHandlerMapping
org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport$EmptyHandlerMapping
org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport$EmptyHandlerMapping
org.springframework.web.servlet.handler.SimpleUrlHandlerMapping

The problem seems to be with SimpleUrlHandlerMapping (at least it seems to be used for the resource I call - api/forward/sample while for api/sample RequestMappingHandlerMapping is in use) which has empty adoptedIterceptors in the case with Java based configuration.

EDIT 2:

Full source code for sample application (I tried to make it as small as possible just to demonstrate the effect): https://github.com/szprutamich/spring-demo

In class ConfigurationBase - configuration can be switched from xml based to java based with static field CONFIG.

With xml based config both urls work:

/api/sample
/api/forward/sample

With java based config forward does not work.

Answer 1

Your question is about a "not existing request mapping", but in your XML configuration, it exists :

<default-servlet-handler xmlns="http://www.springframework.org/schema/mvc" /> This declares a default handler for all requests, and a request interceptor ony works if a valid handler is found. Remove this line and you will get the same behavior in both XML and Java configs : no default handler will be found and the interceptor won't work.

So for the interceptor to work on all requests in your Java configuration, you have to declare a default handler. You could override configureDefaultServletHandling but afaik it's not possible to configure interceptors on it. You may have to explicitly map /** in a default handling controller.