This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
JspContext serves as the base class for the PageContext class and abstracts all
information that is not specific to servlets. This allows for Simple Tag Extensions
to be used outside of the context of a request/response Servlet.
As we are using SimpleTags always in an environment that is Servlet-based (in JSPs, those are Servlets) you can safely downcast the JspContext to the PageContext object.