Jakarta Struts Cookbook

2.5. Factoring Your Application into Modules

Problem

You want to segregate portions of a web application into distinct subapplications, or modules, each with its own separate configuration.

Solution

Create a Struts configuration file for each module in addition to a Struts configuration file for the default module. Then declare each module using initialization parameters for the ActionServlet in the web.xml, as shown in Example 2-11.

Example 2-11. ActionServlet configuration for modules

<!-- Action Servlet Configuration -->
<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</param-value>
  </init-param>
  <init-param>
    <param-name>config/module1</param-name>
    <param-value>/WEB-INF/struts-config-module1.xml</param-value>
  </init-param>
  <init-param>
    <param-name>config/module2</param-name>
    <param-value>/WEB-INF/struts-config-module2.xml</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
</servlet>

Discussion

Struts 1.1 introduced the ability to define separately configurable sub-applications known as modules. Modules were incorporated into Struts to address the need for subdividing a web application into distinct, manageable portions. Each module is defined with its own configuration file(s). Every Struts application implicitly has a default module. The default module has no module name.

Tip

To provide backward compatibility with Struts ...