code: public static ReadRequest checkRequest(final HttpServletRequest request,
  			final ReadResponse readResponse) {
  		final Node user = checkUserIdentifier(request, readResponse);
  		if (user != null) {
  			final Node poster = checkPosterIdentifier(request, readResponse);
  			if (poster != null) {
  				final int numItems = checkNumItems(request, readResponse);
  				if (numItems != 0) {
  					final Boolean ownUpdates = checkOwnUpdates(request,
  							readResponse);
  					if (ownUpdates != null) {
  						return new ReadRequest(user, poster, numItems,
  								ownUpdates);
  					}
  				}
  			}
  		}
  
  		return null;
  	}
docs: check a read request for validity concerning NSSP
  
  @param request
  Tomcat servlet request
  @param readResponse
  read response object
  @return read request object<br>
  <b>null</b> if the read request is invalid