Rule Definition
When Struts framework is used, it must be used for every page in the application to avoid mixing different technologies and creating an application difficult to maintain and be the source of a lack of robustness.

Remediation
Adapt the application to use Struts for all HTTP Servlets.

Violation Code Sample

---> web.xml

<!-- Struts Action Servlet -->
  <servlet>
    <servlet-name>action</servlet-name>
    <servlet-class>
      org.apache.struts.action.ActionServlet
    </servlet-class>
    <init-param>
      <param-name>config</param-name>
      <param-value>/WEB-INF/conf/struts-config.xml</param-value>
    </init-param>
  <servlet>

  <servlet>
    <servlet-name>AnotherServlet</servlet-name>
    <servlet-class>
      // doesn't inherit from org.apache.struts.action.ActionServlet
      // but inherits from javax.servlet.http.HttpServlet
      com.cast.AnotherServlet // VIOLATION:    
   </servlet-class>
  </servlet>

Fixed Code Sample

<servlet>     <servlet-name>action</servlet-name>     <servlet-class>       org.apache.struts.action.ActionServlet     </servlet-class>     <init-param>       <param-name>config</param-name>       <param-value>/WEB-INF/conf/struts-config.xml</param-value>     </init-param> <servlet>