groovy-core/src/examples/webapps/template-examples/WEB-INF/web.xml

<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
    version="2.4">

<servlet>
    <servlet-name>template</servlet-name>
    <servlet-class>groovy.servlet.TemplateServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>template</servlet-name>
    <url-pattern>*.htm</url-pattern>
  </servlet-mapping>
  
  <servlet-mapping>
    <servlet-name>template</servlet-name>
    <url-pattern>*.html</url-pattern>
  </servlet-mapping>

  <servlet-mapping>
    <servlet-name>template</servlet-name>
    <url-pattern>*.template</url-pattern>
  </servlet-mapping>

</web-app>