A base configuration file named struts-default.xml is included in the struts2.jar file. This file may be included at the top of your struts.xml file to include the standard configuration settings without having to copy them. Here's an example:
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<include file="struts-default.xml"/>
<package name="default" extends="struts-default">
...
</package>
</struts>
The contents of struts-default.xml are here:
Error formatting macro: snippet: java.lang.NullPointerException
This file defines all of the default bundled results and interceptors and many interceptor stacks which you can use either as-is or as a basis for your own application-specific interceptor stacks. Notice the name of the package is "struts-default".