J2EE: Retrieve parameters from the pageContext using "dotted" paths

Hi all,

I am writing in the hope that someone like me have to face the same problem:

Retrieve an attribute that is inside a bean contained in the pageContext using a string key, such as those used in a JSP expression language (eg ${beanName1.beanName2.attribute1}). My intent is to use strings like that: "beanName1.beanName2.attribute1" to retrieve variables in the session or request, within a Custom Tag.

I do not having to reinvent the wheel.