调用的是SDK的方法，Map<String, String> data = new HashMap<String, String>();
//out_refund_no
data.put("out_trade_no", orderNo);
//微信退款单位是分，1分钱 "1"
BigDecimal multiply = amount.multiply(new BigDecimal(100));
logger.info("weChatRefundOrder：multiply-->" + multiply);
data.put("refund_fee", multiply.toBigInteger().toString());
BigDecimal totalBigDecimal = omsOrderDetail.getPayAmount().multiply(new BigDecimal(100));
logger.info("weChatRefundOrder：totalBigDecimal-->" + totalBigDecimal);
data.put("total_fee", totalBigDecimal.toBigInteger().toString());
logger.info("weChatRefundOrder：total_fee-->" + totalBigDecimal.toBigInteger().toString());
data.put("fee_type", "CNY");
//退款单号，用于多次退款
data.put("out_refund_no", outRefundNo);
logger.info("weChatRefundOrder：resp-->");
logger.info("weChatRefundOrder：wxpay-->" + wxpay);
Map<String, String> resp = wxpay.refund(data);
logger.info("weChatRefundOrder：resp-->" + resp);
String result = JSON.toJSONString(resp, SerializerFeature.WriteMapNullValue);
logger.info("weChatRefundOrder：result-->" + result);