LoggingFilter_Part6.java

private static void logRequestHeader(ContentCachingRequestWrapper request, String prefix) {
        String queryString = request.getQueryString();
        if (queryString == null) {
            logger.info("{} {} {}", prefix, request.getMethod(), request.getRequestURI());
        } else {
            logger.info("{} {} {}?{}", prefix, request.getMethod(), request.getRequestURI(), queryString);
        }
        Collections.list(request.getHeaderNames()).forEach(headerName ->
                Collections.list(request.getHeaders(headerName)).forEach(headerValue -> logger.info("{} {} {}", prefix, headerName, headerValue)));
        logger.info("{}", prefix);
    }