public static String toHtml(String raw) {
        MutableDataHolder options = new MutableDataSet();
        List<Extension> extensions = Lists.newArrayList();
        options.set(Parser.EXTENSIONS, extensions);

        // change soft break to hard break
        options.set(HtmlRenderer.SOFT_BREAK, "<br/>");

        Parser parser = Parser.builder(options).build();
        Node document = parser.parse(raw);
        HtmlRenderer renderer = HtmlRenderer.builder(options).build();
        return renderer.render(document);
    }

    public static void main(String[] args) {
        String str = "Incorrect: [amazon][2]\r\n" +
                "\r\n" +
                "[1]: http://www.google.com/\r\n" +
                "[2]: http://www.amazon.com/";
        System.out.println(toHtml(str));
    }