PHP微信支付结果通知与回调策略分析

$str='<xml><return_code><![CDATA[SUCCESS]]></return_code><return_msg><![CDATA[OK]]></return_msg></xml>';
exit($str);

//微信支付回调
public function order_notice(){
    $xml = $GLOBALS['HTTP_RAW_POST_DATA'];
    //将服务器返回的XML数据转化为数组
    $data = $this->FromXml($xml);
    // 保存微信服务器返回的签名sign
    $data_sign = $data['sign'];
    // sign不参与签名算法
    unset($data['sign']);
    //$sign = self::makeSign($data);
    $sign = $this->makeSign($data);
    Clog::setLog($data,'order_notice');
    // 判断签名是否正确 判断支付状态
    if ( ($sign===$data_sign) && ($data['return_code']=='SUCCESS') && ($data['result_code']=='SUCCESS') ) {
      //获取服务器返回的数据
      $order_num = $data['out_trade_no'];     //订单单号
      $openid = $data['openid'];         //付款人openID
      $total_fee = $data['total_fee'];      //付款金额
      $transaction_id = $data['transaction_id']; //微信支付流水号
      $res = $this->order_notice_data_deal($order_num,$openid,$total_fee,$transaction_id);
      if (!$res) {
        $result = -2;
      } else {
        $result = 0;
      }
    }else{
      $result = -1;
    }
    // 返回状态给微信服务器
    if ($result == 0) { // 成功之后不会再回调
      $str='<xml><return_code><![CDATA[SUCCESS]]></return_code><return_msg><![CDATA[OK]]></return_msg></xml>';
    } elseif ($result == -1){ // 失败后会继续发送几次回调
      $str='<xml><return_code><![CDATA[FAIL]]></return_code><return_msg><![CDATA[签名失败]]></return_msg></xml>';
    } elseif ($result == -2) { // 失败后会继续发送几次回调
      $str='<xml><return_code><![CDATA[FAIL]]></return_code><return_msg><![CDATA[更改状态失败]]></return_msg></xml>';
    }
    Clog::setLog($result,'order_notice_result');
    exit($str);
}

public function ToXml($array){
    if(!is_array($array)|| count($array) <= 0){
      return ;
    }
    $xml = '<xml version="1.0">';
    foreach ($array as $key=>$val){
      if (is_numeric($val)){
        $xml.="<".$key.">".$val."</".$key.">";
      }else{
        $xml.="<".$key."><![CDATA[".$val."]]></".$key.">";
      }
    }
    $xml.="</xml>";
    return $xml;
}
public function FromXml($xml){
    if(!$xml){
      // 人工抛出错误
      throw new Exception("xml数据异常！");
    }
    //将XML转为array
    //禁止引用外部xml实体
    libxml_disable_entity_loader(true);
    $this->values = json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA)), true);
    return $this->values;
}
public function MakeSign($data)
{
    //签名步骤一按字典序排序参数
    ksort($data);
    $string = $this->ToUrlParams($data);
    //签名步骤二在string后加入KEY
    $string = $string . "&key=".C('WEIXIN_PAY_KEY');
    //签名步骤三MD5加密
    $string = md5($string);
    //签名步骤四所有字符转为大写
    $result = strtoupper($string);
    return $result;
}
public function ToUrlParams($array)
{
    $buff = "";
    foreach ($array as $k => $v)
    {
      if($k != "sign" && $v != "" && !is_array($v)){
        $buff .= $k . "=" . $v . "&";
      }
    }
    $buff = trim($buff, "&");
    return $buff;
}
// createNonceStr
public function createNonceStr($length = 16) {
    $chars = "abcdefghijklmnopqrstuvwxyz0123456789";
    $str ="";
    for ( $i = 0; $i < $length; $i++ ) {
      $str .= substr($chars, mt_rand(0, strlen($chars)-1), 1);
    }
    return $str;
}