struts.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
    <constant name="struts.devMode" value="true" />

    <package name="user" namespace="/user" extends="struts-default">
        <default-action-ref name="index"></default-action-ref>
        <!-- 全局结果集，本包内及继承自本包的Action可用 -->
        <global-results>
            <result name="mainpage">/mainpage.jsp</result>
        </global-results>

        <action name="index">
            <result>/index.jsp</result>
        </action>

        <action name="r1" class="com.bebig.struts2.user.action.UserAction">
            <result> /success.jsp</result>
            <result name="error"> /error.jsp</result>
        </action>

    </package>

    <!-- 继承自user包，因此可以使用user包的全局结果集 -->
    <package name="admin" namespace="/admin" extends="user">
        <action name="admin" class="com.bebig.struts2.user.action.AdminAction">
            <result> /success.jsp</result>
        </action>
    </package>


</struts>