示例:长链接:https://www.baidu.com?a=1&b=2

域名:www.baidu.com

static String getDomainUrl(String url) {
        String domainUrl = "";
        Pattern p = Pattern.compile("(?<=//|)((\\w)+\\.)+\\w+");
        Matcher m = p.matcher(url);
        if (m.find()) {
            domainUrl = m.group();
        }
        return domainUrl;
    }