public String getPublishDate( String url, String rulePublishDate, String encode ) {
        String publishDateStr = null;
        try {
            SimpleDateFormat dateFormat = null;
            if ( rulePublishDate.equals("xxxx-xx/xx") ) {
                dateFormat = new SimpleDateFormat("yyyy-MM/dd");
                String now = dateFormat.format(new Date());
                now = now.substring(0, 8);
                publishDateStr = url.substring(url.indexOf(now), url.indexOf(now)+10);
            }
            else if ( rulePublishDate.equals("xxxxxxxx") ) {
                dateFormat = new SimpleDateFormat("yyyyMMdd");
                String now = dateFormat.format(new Date());
                now = now.substring(0, 6);
                publishDateStr = url.substring(url.indexOf(now), url.indexOf(now)+8);
            }
            else if ( rulePublishDate.equals("xxxx年xx月xx日") ) {
                dateFormat = new SimpleDateFormat("yyyy年MM月dd日");
                Document doc = getDocument(url, encode);
                publishDateStr = doc.select("span[class=blue2]").last().text();
                publishDateStr = publishDateStr.substring(0, publishDateStr.indexOf("星期")-1);
            }
            if ( publishDateStr == null )
                return null;
            Date publishDate = dateFormat.parse(publishDateStr);
            dateFormat = new SimpleDateFormat("yyyy-MM-dd");
            publishDateStr = dateFormat.format(publishDate);
        }catch (Exception e) {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            e.printStackTrace(new PrintStream(baos));
            NewsEyeSpider.logger.debug(baos.toString());
        }
        return publishDateStr;
    }