Default Servlet

Spring MVC allows for mapping the DispatcherServlet to / (thus overriding the mapping of the container’s default Servlet), while still allowing static resource requests to be handled by the container’s default Servlet. It configures a DefaultServletHttpRequestHandler with a URL mapping of /** and the lowest priority relative to other URL mappings.

This handler forwards all requests to the default Servlet. Therefore, it must remain last in the order of all other URL HandlerMappings. That is the case if you use <mvc:annotation-driven>. Alternatively, if you set up your own customized HandlerMapping instance, be sure to set its order property to a value lower than that of the DefaultServletHttpRequestHandler, which is Integer.MAX_VALUE.

The following example shows how to enable the feature by using the default setup:

  • Java

  • Kotlin

  • Xml

@Configuration
public class WebConfiguration implements WebMvcConfigurer {

	@Override
	public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
		configurer.enable();
	}
}
@Configuration
class WebConfiguration : WebMvcConfigurer {

	override fun configureDefaultServletHandling(configurer: DefaultServletHandlerConfigurer) {
		configurer.enable()
	}
}
<mvc:default-servlet-handler/>

The caveat to overriding the / Servlet mapping is that the RequestDispatcher for the default Servlet must be retrieved by name rather than by path. The DefaultServletHttpRequestHandler tries to auto-detect the default Servlet for the container at startup time, using a list of known names for most of the major Servlet containers (including Tomcat, Jetty, GlassFish, JBoss, WebLogic, and WebSphere). If the default Servlet has been custom-configured with a different name, or if a different Servlet container is being used where the default Servlet name is unknown, then you must explicitly provide the default Servlet’s name, as the following example shows:

  • Java

  • Kotlin

  • Xml

@Configuration
public class CustomDefaultServletConfiguration implements WebMvcConfigurer {

	@Override
	public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
		configurer.enable("myCustomDefaultServlet");
	}
}
@Configuration
class CustomDefaultServletConfiguration : WebMvcConfigurer {

	override fun configureDefaultServletHandling(configurer: DefaultServletHandlerConfigurer) {
		configurer.enable("myCustomDefaultServlet")
	}
}
<mvc:default-servlet-handler default-servlet-name="myCustomDefaultServlet"/>