Static resource serving in SpringMVC

Question

I am using SpringMVC and trying to use pure HTML + JS as the view. I noticed that there are potentially 3 possible places that could handle a static resource like login.html. They are:

1. The controller handler method which is mapped to a seemingly static resource URL.

   @RequestMapping(value = "login.html")
   public String doLogin(Model model) {
       return "login";
   }
   

2. The addResourceHandlers which designates the static resource type and location:

   public void addResourceHandlers(ResourceHandlerRegistry registry) {
      registry.addResourceHandler("*.html").addResourceLocations(("/static/"));
   }
   

3. And Tomcat's DefaultServlet, which by definition, is meant to serve static resources. And can be enabled in SpringMVC as below:

   @Override
   public void configureDefaultServletHandling(
           DefaultServletHandlerConfigurer configurer) {
       // TODO Auto-generated method stub
       configurer.enable();
   }
   

My questions are:

• How does a servlet container like Tomcat determine a resource is static or not? Is it based on some well-known file name extension?
• What's the precedence of the 3 options above?
• What's the relationship between the Spring configuration method addResourceHandler() and the Tomcat DefaultServlet? My guess is addResourceHandler() tells DefaultServlet where to find certain type of static resources.

Some related links:

21.16.9 Serving of Resources

Resource served by SpringMVC's ResourceHttpRequestHandler.

21.16.10 Falling Back On the "Default" Servlet To Serve Resources

Resource served by servlet container's DefaultServet via SpringMVC's DefaultServletHttpRequestHandler