微信公众号支付整体流程记录备忘

1. 商户server调用统一下单接口请求订单，api参见公共api【统一下单API】
2. 商户server接收支付通知，api参见公共api【支付结果通知API】
3. 商户server查询支付结果，api参见公共api【查询订单API】

https://open.weixin.qq.com/connect/oauth2/authorize?appid=APPID&redirect_uri=REDIRECT_URI&response_type=code&scope=SCOPE&state=STATE#wechat_redirect

https://open.weixin.qq.com/connect/oauth2/authorize?appid=${appid}&redirect_uri={{url}}%2Fwxpay%2FpayModelAndView?parameterName=${xxxx}&response_type=code&scope=snsapi_base&state=123#wechat_redirect

https://api.weixin.qq.com/sns/oauth2/access_token?appid=APPID&secret=SECRET&code=CODE&grant_type=authorization_code

public String getSign(Map<String, String> items, String APISecret) throws NoSuchAlgorithmException, UnsupportedEncodingException {
        Map<String, String> tmp = new TreeMap<String, String>(items);
        StringBuilder sb = new StringBuilder();
        for(Map.Entry<String, String> entry : tmp.entrySet()) {
            String key = entry.getKey();
            String value = entry.getValue();
            if(StringUtils.isEmpty(value)) continue;
            sb.append(key).append("=").append(value).append("&");
        }
        sb.append("key=").append(APISecret);

        return publicService.padStr(new BigInteger(1, MessageDigest.getInstance("MD5").digest(sb.toString().getBytes(CharEncoding.UTF_8))).toString(16).toUpperCase(), "0", 32);
    }

//将userId和out_trade_no等信息写入payment_result表
paymentPublicService.insertStubToPaymentResultTable(userId, PaymentResult.CHANNEL.WEIXIN, coachProductId, outTradeNo);

$(function(){
  alert("xxxxxxxx");
  callPay();
  function onBridgeReady(){
    WeixinJSBridge.invoke(
            'getBrandWCPayRequest', {
              "appId" : '${appId}',           //公e众号名称，由商户传入
              "timeStamp": '${timeStamp}',    //时间戳，自1970年以来的秒数
              "nonceStr" : '${nonceStr}',     //随机串
              "package" : '${package1}',      //预支付ID参数
              "signType" : '${signType}',     //微信签名方式:
              "paySign" : '${paySign}'        //微信签名
            },
            function(res){
              if(res.err_msg == "get_brand_wcpay_request:ok" ) {
                alert("支付成功");
                window.location.href="/student/student_booking";
              }else if(res.err_msg == "get_brand_wcpay_request:cancel" ){
                alert("支付过程中用户取消");
                window.location.href="student_pay.jsp";
              }else{
                alert('支付失败');
                window.location.href="student_pay.jsp";
              }
            }
    );
  }
  function callPay(){
    if (typeof WeixinJSBridge == "undefined"){
      if( document.addEventListener ){
        document.addEventListener('WeixinJSBridgeReady', onBridgeReady, false);
      }else if (document.attachEvent){
        document.attachEvent('WeixinJSBridgeReady', onBridgeReady);
        document.attachEvent('onWeixinJSBridgeReady', onBridgeReady);
      }
    }else{
      onBridgeReady();
    }
  }
})

 String xml = IOUtils.toString(request.getInputStream(), CharEncoding.UTF_8);

<xml>
     <return_code><![CDATA[SUCCESS]]></return_code>
     <return_msg><![CDATA[OK]]></return_msg>
</xml>