code: public QrPayResponse qrPay(QrPayRequest request, Boolean convert){
  
          checkPayParams(request);
  
          Map<String, Object> respData = doQrPay(request, TradeType.NATIVE);
  
          String codeUrl = String.valueOf(respData.get(WepayField.CODE_URL));
          if (convert){
              try {
                  codeUrl = LIANTU_URL + URLEncoder.encode(codeUrl, "UTF-8");
              } catch (UnsupportedEncodingException e) {
                  throw new WepayException(e);
              }
          }
  
          String prepayId = String.valueOf(respData.get(WepayField.PREPAY_ID));
  
          QrPayResponse resp = new QrPayResponse();
          resp.setCodeUrl(codeUrl);
          resp.setPrepayId(prepayId);
  
          return resp;
      }
docs: 动态二维码支付(NATIVE)
  @param request 支付请求对象
  @param convert 是否转换为二维码图片链接(使用联图)
  @return 可访问的二维码链接，或抛WepayException