This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Rather than guessing, why don't you put in some diagnostic statements to show whether getServletContext() is indeed returning null or not.
Btw, where in your servlet does this statement appear?
Also, you do not need to do anything in your web.xml to "initiliaze the servlet context". The context-param element you posted does nothing except establish a context parameter with the name of "none".