thinkPHP and onethink micropayment plugin

//实现的Wxpay钩子方法
        public function Wxpay($param){
            require './Addons/Wxpay/WxPayPubHelper/WxPayPubHelper.php';
            $jsApi = new \JsApi_pub(); 
             
            //=========步骤1：网页授权获取用户openid============
            if (!isset($_GET['code']))
            {
                //触发微信返回code码
                $url = $jsApi->createOauthUrlForCode(\WxPayConf_pub::JS_API_CALL_URL.'/order_id/'.$param['order_id']);
                Header("Location: $url");
            }else
            {
                $order_id = $param['order_id'];
                $info = M('Order')->where('id='.$order_id)->find();
                if(empty($info) || $info['is_pay'] == 1){
                    dump('该订单不存在或已支付'.$order_id);
                    exit();
                }
                $this->assign('info', $info);
                $a = $info['money'];
                $b = 100;
                $c = $a * $b;
                 
                //获取code码，以获取openid
                $code = $_GET['code'];
                $jsApi->setCode($code);
                $openid = $jsApi->getOpenId();
            }
              
            //=========步骤2：使用统一支付接口，获取prepay_id============
            //使用统一支付接口
            $unifiedOrder = new \UnifiedOrder_pub();
              
            $unifiedOrder->setParameter("openid","$openid");//商品描述
            $unifiedOrder->setParameter("body","在线预订");//商品描述
            //自定义订单号，此处仅作举例
            $timeStamp = time();
//             $out_trade_no = \WxPayConf_pub::APPID."$timeStamp";
            $out_trade_no = $info['ordersn'];
            $unifiedOrder->setParameter("out_trade_no", "$out_trade_no");//商户订单号
            $unifiedOrder->setParameter("total_fee", "$c");//总金额
            $unifiedOrder->setParameter("notify_url",\WxPayConf_pub::NOTIFY_URL.'/order_id/'.$param['order_id']);//通知地址
            $unifiedOrder->setParameter("trade_type","JSAPI");//交易类型
              
            $prepay_id = $unifiedOrder->getPrepayId();
            //=========步骤3：使用jsapi调起支付============
            $jsApi->setPrepayId($prepay_id);
            $jsApiParameters = $jsApi->getParameters();
            $this->assign('jsApiParameters', $jsApiParameters);
 
            $this->display('pay');
        }