Jakarta Struts Cookbook

2.4. Using Multiple Struts Configuration Files

Problem

You want to break apart a large struts-config.xml file into smaller files for improved organization and easier maintenance, particularly in a team environment.

Solution

Split your monolithic struts-config.xml into multiple configuration files. Each file must be well-formed and valid according to the struts-config XML DTD. Reference these files as the value for the config initialization parameter of the ActionServlet in the web.xml file as shown in Example 2-9.

Example 2-9. Multiple config files (single module)

<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/struts-config.xml,
      /WEB-INF/struts-config-2.xml
    </param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
</servlet>

When the ActionServlet is loaded, Struts will merge the results of the specified configuration files into a single in-memory configuration.

Discussion

For anything other than the most trivial applications, the struts-config.xml file tends to get large and unwieldy. Many applications may have action elements numbering in the hundreds. Combine this with the use of a locking source control system, and soon you will have developers in constant contention for the same file.

Struts 1.1 introduced support for multiple configuration files. Each configuration file must be a valid XML file and conform to the struts-config XML Document ...