code: void logException(HttpServletRequest req, Level level, String sourceMethod, Throwable t) {
  		if (log.isLoggable(level)) {
  			StringBuffer sb = new StringBuffer();
  			// add the request URI and query args
  			String uri = req.getRequestURI();
  			if (uri != null) {
  				sb.append(uri);
  				String queryArgs = req.getQueryString();
  				if (queryArgs != null) {
  					sb.append("?").append(queryArgs); //$NON-NLS-1$
  				}
  			}
  			// append the exception class name
  			sb.append(": ").append(t.getClass().getName()); //$NON-NLS-1$
  			// append the exception message
  			sb.append(" - ").append(t.getMessage() != null ? t.getMessage() : "null");  //$NON-NLS-1$//$NON-NLS-2$
  			log.logp(level, AbstractAggregatorImpl.class.getName(), sourceMethod, sb.toString(), t);
  		}
  	}
docs: Formats and logs an exception log message including the request url, query args, the exception class
  name and exception message.
  
  @param req
  the http servlet request
  @param level
  the logging level
  @param sourceMethod
  the calling method name
  @param t
  the exception