利用定时器的方式实现主动查询订单支付状态

在我们对接微信支付的时候可能会出现用户支付了，但我们系统业务支付状态并没有改变的情况，这是因为微信推送支付数据流的时候是后台通知交互时，

如果微信收到商户的应答不符合规范或超时，微信会判定本次通知失败，重新发送通知，直到成功为止（在通知一直不成功的情况下，微信总共会发起10次通知，

通知频率为15s/15s/30s/3m/10m/20m/30m/30m/30m/60m/3h/3h/3h/6h/6h - 总计 24h4m），但微信不保证通知最终一定能成功。

所以这里就需要我们自己主动去查询：接口详细说明地址（http://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_2）

  //创建一个定时器主动查询订单支付状态
        Timer timer = new Timer();
        timer.schedule(new TimerTask() {

            //最大重试次数
            int MAX_RETRY = 5;

            @Override
            public void run() {

                MAX_RETRY--;

                //检查订单系统
                WxpOrderDTO wxpOrderDTO = 
                             wxpOrderMapper.selectWxpOrder(orderNo);

                if (wxpOrderDTO.getStatus().equals("1")) {

                    //取消定时器(订单支付成功)
                    timer.cancel();

                } else {

                    //查询订单状态
                    WxMpPayResult payResult = wxMpService.getJSSDKPayResult(null, orderNo);
                    if (payResult.getReturn_code().equals("SUCCESS")) {

                        //已经支付，更新订单状态
                        if (payResult.getResult_code().equals("SUCCESS")) {
                            wxpOrderMapper.updateOrderStatus(orderNo);
                        }

                    }

                }

                if (MAX_RETRY == 0) {

                    //取消定时器(用户取消支付)
                    timer.cancel();

                }


            }

        }, 2000, 5000);

  /**
     * 该接口提供所有微信支付订单的查询,当支付通知处理异常戒丢失的情冴,商户可以通过该接口查询订单支付状态。
     * 详见http://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_2
     * @param transactionId
     * @param outTradeNo
     */
    WxMpPayResult getJSSDKPayResult(String transactionId, String outTradeNo);

 @Override
  public WxMpPayResult getJSSDKPayResult(String transactionId, String outTradeNo) {
    String nonce_str = System.currentTimeMillis() + "";

    SortedMap<String, String> packageParams = new TreeMap<String, String>();
    packageParams.put("appid", wxMpConfigStorage.getAppId());
    packageParams.put("mch_id", wxMpConfigStorage.getPartnerId());
    if (transactionId != null && !"".equals(transactionId.trim()))
      packageParams.put("transaction_id", transactionId);
    else if (outTradeNo != null && !"".equals(outTradeNo.trim()))
      packageParams.put("out_trade_no", outTradeNo);
    else
      throw new IllegalArgumentException("Either 'transactionId' or 'outTradeNo' must be given.");
    packageParams.put("nonce_str", nonce_str);
    packageParams.put("sign", WxCryptUtil.createSign(packageParams, wxMpConfigStorage.getPartnerKey()));

    StringBuilder request = new StringBuilder("<xml>");
    for (Entry<String, String> para : packageParams.entrySet()) {
      request.append(String.format("<%s>%s</%s>", para.getKey(), para.getValue(), para.getKey()));
    }
    request.append("</xml>");

    HttpPost httpPost = new HttpPost("https://api.mch.weixin.qq.com/pay/orderquery");
    if (httpProxy != null) {
      RequestConfig config = RequestConfig.custom().setProxy(httpProxy).build();
      httpPost.setConfig(config);
    }

    StringEntity entity = new StringEntity(request.toString(), Consts.UTF_8);
    httpPost.setEntity(entity);
    try {
      CloseableHttpResponse response = httpClient.execute(httpPost);
      String responseContent = Utf8ResponseHandler.INSTANCE.handleResponse(response);
      XStream xstream = XStreamInitializer.getInstance();
      xstream.alias("xml", WxMpPayResult.class);
      WxMpPayResult wxMpPayResult = (WxMpPayResult) xstream.fromXML(responseContent);
      return wxMpPayResult;
    } catch (IOException e) {
      throw new RuntimeException("Failed to query order due to IO exception.", e);
    }
  }

哈哈，具体要根据自己的业务来做啊，这里提供一个思路，O(∩_∩)O哈哈~