<p>What is the benefit of using the servletContext as opposed the request in order to obtain a requestDispatcher?</p>

<pre><code>servletContext.getRequestDispatcher(dispatchPath)
</code></pre>

<p>and using </p>

<pre><code>argRequest.getRequestDispatcher(dispatchPath)
</code></pre>

It's there in the javadocs in black and white
http://java.sun.com/javaee/5/docs/api/javax/servlet/ServletRequest.html#getRequestDispatcher(java.lang.String)
The difference between this method and
  ServletContext.getRequestDispatcher(java.lang.String)
  is that this method can take a
  relative path.