微信退款

退款的API比较简单，只需要请求这个接口https://api.mch.weixin.qq.com/secapi/pay/refund，请求体如下：

<xml>
   <appid>wx2421b1c4370ec43b</appid>
   <mch_id>10000100</mch_id>
   <nonce_str>6cefdb308e1e2e8aabd48cf79e546a02</nonce_str>
   <out_refund_no>1415701182</out_refund_no>
   <out_trade_no>1415757673</out_trade_no>
   <refund_fee>1</refund_fee>
   <total_fee>1</total_fee>
   <transaction_id></transaction_id>
   <sign>FE56DD4AA85C0EECA82C35595A69E153</sign>
</xml> 

可参见官方文档申请退款。

使用SDK方式对上面的请求接口请求体都作了封装，只需动态传入一些参数就行了，如下：

/**
 * 退款
 * @param orderDTO
 */
@Override
public RefundResponse refund(OrderDTO orderDTO) {
    RefundRequest refundRequest=new RefundRequest();
    refundRequest.setOrderId(orderDTO.getOrderId());
    refundRequest.setOrderAmount(orderDTO.getOrderAmount().doubleValue());
    refundRequest.setPayTypeEnum(BestPayTypeEnum.WXPAY_H5);
    log.info("【微信退款】 request={}",JsonUtil.toJson(refundRequest));

    RefundResponse refundResponse=bestPayService.refund(refundRequest);
    log.info("【微信退款】 response={}",JsonUtil.toJson(refundResponse));

    return refundResponse;
}

这个方法在取消订单的业务方法里被调用，如下：

@Override
@Transactional
public OrderDTO cancel(OrderDTO orderDTO) {
    OrderMaster orderMaster=new OrderMaster();
//        BeanUtils.copyProperties(orderDTO,orderMaster);

    //判断订单状态
    if(!orderDTO.getOrderStatus().equals(OrderStatusEnum.NEW.getCode())){
        log.error("【取消订单】订单状态不正确, orderId={},orderStatus={}",orderDTO.getOrderId(),orderDTO.getOrderStatus());
        throw new SellException(ResultEnum.ORDER_STATUS_ERROR);
    }
    //修改订单状态
    orderDTO.setOrderStatus(OrderStatusEnum.CANCLE.getCode());
    BeanUtils.copyProperties(orderDTO,orderMaster);
    OrderMaster updateResult=orderMasterRepository.save(orderMaster);
    if(updateResult==null){
        log.error("【取消订单】更新失败,orderMaster={}",orderMaster);
        throw new SellException(ResultEnum.ORDER_UPDATE_FAIL);
    }

    //返还库存
    if(CollectionUtils.isEmpty(orderDTO.getOrderDetailList())){
        log.error("【取消订单】订单中无商品详情，orderDTO={}",orderDTO);
        throw new SellException(ResultEnum.ORDER_DETAIL_EMPTY);
    }
    List<CartDTO> cartDTOList=orderDTO.getOrderDetailList().stream()
            .map(e->new CartDTO(e.getProductId(),e.getProductQuantity()))
            .collect(Collectors.toList());
    productService.increaseStock(cartDTOList);

    //如果已支付，需要退款
    if(orderDTO.getPayStatus().equals(PayStatusEnum.SUCCESS.getCode())){
        payService.refund(orderDTO);
    }

    return orderDTO;
}