class DefQaListLink implements QaListLink, Serializable {

    @Override
    public List<String> getQaLinks(String listUrl) {
        logger.info("查询：" + listUrl);
        Set<String> urlLinks = new HashSet<String>();
        Document doc = HtmlDocumentUtil.urlToDocument(listUrl);
        if (HtmlDocumentUtil.validateDocument(doc)) {
            Elements links = doc.select("a[href]");
            String parseUrl;
            try {
                for (Element link : links) {
                    parseUrl = link.attr("abs:href").trim();
                    if(StringUtils.isEmpty(parseUrl))
                        continue;
                    if (parseUrl.contains(NANGJING_QA_LINK_RULE)) {
                        urlLinks.add(parseUrl);
                    }
                }
            } catch (PatternSyntaxException e) {
                return new ArrayList<String>(urlLinks);
            }

        }
        return new ArrayList<String>(urlLinks);
    }

}