private void tramsformToHtml(Transformer transformer, File xmlFile) {
        if (transformer != null) {
            File html = new File("logs/html/" + xmlFile.getName() + ".html");
            if (!html.exists()) {
                boolean success;
                try {
                    success = html.createNewFile();
                    if (!success) {
                        throw new IOException();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                    System.err.println("can not create file: " + html.getAbsolutePath());
                }
            }

            transformer.setParameter("logName", xmlFile.getName());

            try {
                transformer.transform(new StreamSource(xmlFile), new StreamResult(html));
            } catch (TransformerException e) {
                e.printStackTrace();
                System.err.println("transformer exception: " + e.getMessage());
            }
        }
    }