final Map<String, List<String>> params = new HashMap<>();
        for (final Map.Entry<String, String[]> e : request.getParameterMap().entrySet()) {
            if (e.getValue().length > 0) {
                params.put(e.getKey(), Arrays.asList(e.getValue()));
            }
        }
        if (logger.isDebugEnabled()) {
            logger.debug("process authentication: url: {}, params: {}", urlBuf, params);
        }