Can I have more than one struts-config.xml file for a single Struts application?

Yes! One can have more than one struts-config.xml file for a single Struts application.
You can define different struts-conifg.xml file for different modules in a single web application. It is useful when you are developing a distributed application. But you must enter those struts-config.xml files details in deployment descripter (i.e., web.xml) file.

If you are working with multiple modules in your project, then you can have one configuration file for each modules. Let's say the project has two modules admin and reports. You access the admin screens using the URI admin/admin-module1 and reports using the URI report/report-1. Here the admin and report are two different modules.
The following code shows how to create a seperate configuration file for each module.

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 id="WebApp_ID" version="2.5">
 <display-name>StrutsExample2</display-name>

 <servlet>
  <servlet-name>action</servlet-name>
  <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
  <init-param>
   <param-name>config/admin</param-name>
   <param-value>/WEB-INF/struts-config-admin.xml</param-value>
  </init-param>
  <init-param>
   <param-name>config/report</param-name>
   <param-value>/WEB-INF/struts-config-report.xml</param-value>
  </init-param>
  <load-on-startup>2</load-on-startup>
 </servlet>

 <servlet-mapping>
  <servlet-name>action</servlet-name>
  <url-pattern>*.do</url-pattern>
 </servlet-mapping>

 <welcome-file-list>
  <welcome-file>index.jsp</welcome-file>
 </welcome-file-list>
</web-app>

If param-name is same for the application we can configure mutliple struts-configuration files in param-value by separating with commas.

For Example:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 id="WebApp_ID" version="2.5">
 <display-name>StrutsExample2</display-name>

 <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-config1.xml,/WEB-INF/struts-config2.xml,/WEB-INF/struts-config3.xml</param-value>
  </init-param>
  <load-on-startup>2</load-on-startup>
 </servlet>

 <servlet-mapping>
  <servlet-name>action</servlet-name>
  <url-pattern>*.do</url-pattern>
 </servlet-mapping>

 <welcome-file-list>
  <welcome-file>index.jsp</welcome-file>
 </welcome-file-list>
</web-app>

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