public String parseXml(){
     String nationalB = "Нац. Банк";
  try {
      URL url = new URL("http://www.nationalbank.kz/rss/rates_all.xml");
      URLConnection conn = url.openConnection();
      DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
      DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
      Document document = documentBuilder.parse(conn.getInputStream());

      NodeList list = document.getElementsByTagName("channel");
      String usd = "", course = "", pubDate = "";
      for (int i = 0; i < list.getLength(); i ++){
          Node node = list.item(i);
          Element element = (Element)node;
          if (node.getNodeType() == Node.ELEMENT_NODE){
              if (usd == "USD") {
                  course = element.getElementsByTagName("description").item(0).getTextContent();
                  usd = element.getElementsByTagName("title").item(0).getChildNodes().item(0).getNodeValue();
                  pubDate = element.getElementsByTagName("pubDate").item(0).getTextContent();
              }
          }
      }
      return nationalB+" на "+pubDate+"nДоллар :"+course;

  }catch (IOException | ParserConfigurationException | SAXException e){
      e.printStackTrace();
  }
  return nationalB;
  }
}

public void onUpdateReceived(Update update) {
        String usd = parseXml();
        Message message = update.getMessage();
        if (message != null && message.hasText()){
            switch (message.getText()){
                case "/course for today":
                    sendMsg(message, usd);
                    break;
                case "/setting":
                    sendMsg(message, "Что будем настраивать");
                            break;
                    default:
            }
        }

    }