struts2读取request,session,application中的值

  request.---->
<s:property value="#request.mySessionPropKey"/> or
<s:property value="#request['mySessionPropKey']"/> or
<s:property value="#request['myRequestPropKey']"/>
session---->
<s:property value="#session.mySessionPropKey"/> or
<s:property value="#request['mySessionPropKey']"/> or
<s:property value="#request['myRequestPropKey']"/>
application--->
<s:property value="#application.mySessionPropKey"/> or
<s:property value="#application['mySessionPropKey']"/> or
<s:property value="#application['myRequestPropKey']"/>

http://localhost:8080/demo/index.jsp?flag=kkkk
<s:property value="#parameters.flag" />
<s:property value="#parameters.mySessionPropKey"/> or
<s:property value="#parameters['mySessionPropKey']"/> or
<s:property value="#parameters['myRequestPropKey']"/>