@Override
    protected void doHead(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        // Request that the browser revalidate cached data
        response.addHeader("Cache-Control", "no-cache");
        response.addHeader("Pragma", "no-cache");

        // Set last modified and content type headers
        response.addDateHeader("Last-Modified", resource.getLastModified());
        response.setContentType(resource.getMimeType());

    }
Creates a new ResourceServlet which serves the given Resource for all
HTTP GET requests.

@param resource
    The Resource to serve.
guacamole/src/main/java/org/apache/guacamole/resource/ResourceServlet.java