stem is responsible for managing whether or not 
  there is an active HTTP session.

  <p>The getHttpSession method throws <code>JAXRPCException</code> 
  if invoked by an non HTTP bound endpoint.</div>
<dl>
<dt><span class="returnLabel">Returns:</span></dt>
<dd>The HTTP session associated with the current
           invocation or <code>null</code> if there is
           no active session.</dd>
<dt><span class="throwsLabel">Throws:</span></dt>
<dd><code><a href="../../../../javax/xml/rpc/JAXRPCException.htm