"\"data\":" + pingResponse.getMessage());
        } catch (final Exception e) {
            if (logger.isDebugEnabled()) {
                logger.debug("Failed to process a ping request.", e);
            }
            writeJsonResponse(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e);
        }
    }

                logger.error("Failed to read {} from {}", path, filePath);
                throw new WebApiException(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e);
            }
        } else {
            try {
                writeHeaders(response);
                response.sendError(HttpServletResponse.SC_NOT_FOUND, path + " is not found.");
            } catch (final ClientAbortException e) {

                if (OPTIONS.equals(httpRequest.getMethod())) {
                    final HttpServletResponse httpResponse = (HttpServletResponse) response;
                    httpResponse.setStatus(HttpServletResponse.SC_ACCEPTED);
                    return;
                }
            } else if (logger.isDebugEnabled()) {
                logger.debug("No CorsHandler for {}", origin);
            }
        }

                    throw new RequestLoggingFilter.RequestClientErrorException("Your request is not authorized.", "401 Unauthorized",
                            HttpServletResponse.SC_UNAUTHORIZED);
                });
            }

            // assert
            if (null == principal) {
                final String msg = "Principal was null.";