public static Document getJsoupDocumentByUrl(String url) {
		Document doc = null;
		int retry = 0;
		while (retry++ < 5) {
			try {
				doc = Jsoup.connect(url).userAgent(HttpConnectionManager.USER_AGENT).timeout(10000).get();
				if (doc != null) {
					return doc;
				}
			} catch (SocketTimeoutException e) {
				logger.debug(e.getMessage());
			} catch (IOException e) {
				logger.warn(e.getMessage());
				break;
			} catch (Throwable e) {
				logger.error(e.getMessage());
				break;
			}
		}
		return doc;
	}