@Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { try { Payload payload = gson.fromJson(req.getReader(), Payload.class); if (payload != null && payload.getMarkdown() != null) { String html = ""; if (payload.getLinkAttributes() != null && payload.getLinkAttributes().size() > 0) { AttributesLinkRederer linkRenderer = new AttributesLinkRederer(payload.getLinkAttributes()); html = processor.markdownToHtml(payload.getMarkdown(), linkRenderer); } else { html = processor.markdownToHtml(payload.getMarkdown()); } resp.getWriter().write(html); } resp.getWriter().close(); resp.setStatus(200); } catch (Exception e) { e.printStackTrace(); resp.setStatus(500); } }