Excluding Content from url-pattern in Java web.xml

A while ago I blogged about my frustration with my inability to exclude certain URLs from a url-pattern mapping. In short, I wanted to map everything except /static/* to a dispatch servlet.

There is a way to do this, in some servlet servers. Many (most, all?) servlet containers define a default servlet to handle static content. Be default, any unmapped URLs will be handled by the default servlet. However, you can explicitly map certain URLs to this default servlet, achieving a de-facto url-exclude pattern.

Here is an example:

<servlet-mapping>
 <servlet-name>default</servlet-name>
 <url-pattern>/static/*</url-pattern>
</servlet-mapping>

<servlet-mapping>
 <servlet-name>SpringMVCServlet</servlet-name>
 <url-pattern>/*</url-pattern>
</servlet-mapping>

Where in this case, you have SpringMVCServlet defined in your web.xml, but not default. The default servlet definition is inherited from the servlet container.

The order shouldn't matter, as long as your mapping for the default servlet is more specific.

This is known to work in at least Jetty and Tomcat.