php-微信-APP支付

场景介绍
适用于商户在移动端APP中集成微信支付功能。
商户APP调用微信提供的SDK调用微信支付模块，商户APP会跳转到微信中完成支付，支付完后跳回到商户APP内，最后展示支付结果。
目前微信支付支持手机系统有：IOS（苹果）、Android（安卓）和WP（Windows Phone）。

文档参考
https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=8_1

开发步骤
1.生成客户端支付参数
调用统一下单接口获取预授权id，使用预授权id进行二次签名生成客户端调起微信支付所需的参数
2.支付结果通知处理
支付完成后，微信会把相关支付结果和用户信息发送给商户，商户需要接收处理，并返回应答。
对后台通知交互时，如果微信收到商户的应答不是成功或超时，微信认为通知失败，微信会通过一定的策略定期重新发起通知，尽可能提高通知的成功率，但微信不保证通知最终能成功。

原创微信app支付SDK
注：官方没提供

<?php
namespace app\pay\tool;
/**
 * 微信支付服务器端下单
 * 微信APP支付文档地址:  https://pay.weixin.qq.com/wiki/doc/api/app.php?chapter=8_6
 * 使用示例
 * $options = array(
 *        'appid'    =>    '**********',        //填写微信分配的公众账号ID
 *        'mchid'    =>    '********',                //填写微信支付分配的商户号
 *        'notify_url'=>    'http://www.baidu.com/',    //填写微信支付结果回调地址
 *        'key'        =>    ''**********''                //填写微信商户支付密钥
 *    );
 *    统一下单方法
 *    $WechatAppPay = new wechatAppPay($options);
 *    $params['body'] = '商品描述';                        //商品描述
 *    $params['out_trade_no'] = '1217752501201407';    //自定义的订单号
 *    $params['total_fee'] = '100';                    //订单金额 只能为整数 单位为分
 *    $wechatAppPay->unifiedOrder( $params );
 */
class WxpayAppSDK
{
    //接口API URL前缀
    const API_URL_PREFIX = 'https://api.mch.weixin.qq.com';
    //下单地址URL
    const UNIFIEDORDER_URL = "/pay/unifiedorder";
    //查询订单URL
    const ORDERQUERY_URL = "/pay/orderquery";
    //关闭订单URL
    const CLOSEORDER_URL = "/pay/closeorder";

    //公众账号ID
    private $appid;
    //商户号
    private $mch_id;
    //随机字符串
    private $nonce_str;
    //签名
    private $sign;
    //商品描述
    private $body;
    //商户订单号
    private $out_trade_no;
    //支付总金额
    private $total_fee;
    //终端IP
    private $spbill_create_ip;
    //支付结果回调通知地址
    private $notify_url;
    //交易类型
    private $trade_type;
    //支付密钥
    private $key;
    //证书路径
    private $SSLCERT_PATH;
    private $SSLKEY_PATH;
//    保存错误信息
    public $errorMsg = '';
    //所有参数
    private $params = array();

    /**
     * 传入配置信息
     * $options = array(
     *        'appid'    =>    '**********',        //填写微信分配的公众账号ID
     *        'mchid'    =>    '********',                //填写微信支付分配的商户号
     *        'notify_url'=>    'http://www.baidu.com/',    //填写微信支付结果回调地址
     *        'key'        =>    ''**********''                //填写微信商户支付密钥
     *    );
     * WxpayApp constructor.
     * @param $options
     */
    public function __construct($options)
    {
        $this->appid = isset($options['appid']) ? $options['appid'] : '';
        $this->mch_id = isset($options['mchid']) ? $options['mchid'] : '';
        $this->notify_url = isset($options['notify_url']) ? $options['notify_url'] : '';
        $this->key = isset($options['key']) ? $options['key'] : '';
    }


    /**
     * 下单方法->统一下单接口
     * @link https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=9_1
     * @param    $params    下单参数
     */
    public function unifiedOrder($params)
    {
        $this->body = $params['body'];
        $this->out_trade_no = $params['out_trade_no'];
        $this->total_fee = $params['total_fee'];
        $this->trade_type = 'APP';//交易类型 JSAPI | NATIVE |APP | WAP
        $this->nonce_str = $this->genRandomString();
        $this->spbill_create_ip = $_SERVER['REMOTE_ADDR'];

        $this->params['appid'] = $this->appid;
        $this->params['mch_id'] = $this->mch_id;
        $this->params['nonce_str'] = $this->nonce_str;
        $this->params['body'] = $this->body;
        $this->params['out_trade_no'] = $this->out_trade_no;
        $this->params['total_fee'] = $this->total_fee;
        $this->params['spbill_create_ip'] = $this->spbill_create_ip;
        $this->params['notify_url'] = $this->notify_url;
        $this->params['trade_type'] = $this->trade_type;

        //获取签名数据
        $this->sign = $this->MakeSign($this->params);
        $this->params['sign'] = $this->sign;
        $xml = $this->data_to_xml($this->params);
        $response = $this->postXmlCurl($xml, self::API_URL_PREFIX . self::UNIFIEDORDER_URL);
        if (!$response) {
            return false;
        }
        $result = $this->xml_to_data($response);
        if (!empty($result['result_code']) && !empty($result['err_code'])) {
            $result['err_msg'] = $this->error_code($result['err_code']);
        }
        return $result;
    }

    /**
     * 查询订单信息
     * @param $out_trade_no        订单号
     * @return array
     */
    public function orderQuery($out_trade_no)
    {

        $this->params['appid'] = $this->appid;
        $this->params['mch_id'] = $this->mch_id;
        $this->params['nonce_str'] = $this->genRandomString();
        $this->params['out_trade_no'] = $out_trade_no;

        //获取签名数据
        $this->sign = $this->MakeSign($this->params);
        $this->params['sign'] = $this->sign;
        $xml = $this->data_to_xml($this->params);
        $response = $this->postXmlCurl($xml, self::API_URL_PREFIX . self::ORDERQUERY_URL);
        if (!$response) {
            return false;
        }
        $result = $this->xml_to_data($response);
        if (!empty($result['result_code']) && !empty($result['err_code'])) {
            $result['err_msg'] = $this->error_code($result['err_code']);
        }
        return $result;
    }

    /**
     * 关闭订单
     * @param $out_trade_no        订单号
     * @return array
     */
    public function closeOrder($out_trade_no)
    {
        $this->params['appid'] = $this->appid;
        $this->params['mch_id'] = $this->mch_id;
        $this->params['nonce_str'] = $this->genRandomString();
        $this->params['out_trade_no'] = $out_trade_no;

        //获取签名数据
        $this->sign = $this->MakeSign($this->params);
        $this->params['sign'] = $this->sign;
        $xml = $this->data_to_xml($this->params);
        $response = $this->postXmlCurl($xml, self::API_URL_PREFIX . self::CLOSEORDER_URL);
        if (!$response) {
            return false;
        }
        $result = $this->xml_to_data($response);
        return $result;
    }

    /**
     *
     * 获取支付结果通知数据
     * return array
     */
    public function getNotifyData()
    {
        //获取通知的数据
        $xml = file_get_contents("php://input");
        $data = array();
        if (empty($xml)) {
            return false;
        }
        $data = $this->xml_to_data($xml);
        if (!empty($data['return_code'])) {
            if ($data['return_code'] == 'FAIL') {
                return false;
            }
        }
        return $data;
    }

    /**
     * 验证通知签名
     */
    public function verifyNotify($data)
    {
        $sign = $data['sign'];
        unset($data['sign']);
        if ($sign != $this->MakeSign($data)) {
            return false;
        } else {
            return true;
        }

    }

    /**
     * 接收通知成功后应答输出XML数据
     * @param string $xml
     */
    public function replyNotifySuccess()
    {
        $data['return_code'] = 'SUCCESS';
        $data['return_msg'] = 'OK';
        $xml = $this->data_to_xml($data);
        echo $xml;
        die();
    }
    /**
     * 接收通知失败后应答输出XML数据
     * @param string $xml
     */
    public function replyNotifyFail()
    {
        $data['return_code'] = 'Fail';
        $data['return_msg'] = '处理订单失败';
        $xml = $this->data_to_xml($data);
        echo $xml;
        die();
    }


    /**
     * 二次签名，用于客户端调用微信客户端
     * @link https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=9_7&index=3
     * 生成APP端支付参数
     * @param    $prepayid    预支付id
     */
    public function getAppPayParams($prepayid)
    {
        $data['appid'] = $this->appid;
        $data['partnerid'] = $this->mch_id;
        $data['prepayid'] = $prepayid;
        $data['package'] = 'Sign=WXPay';
        $data['noncestr'] = $this->genRandomString();
        $data['timestamp'] = time();
        $data['sign'] = $this->MakeSign($data);
        return $data;
    }

    /**
     * 快速获取签名数据给客户端
     * @param $param
     *                  $params['body'] = '商品描述';                        //商品描述
     *                    $params['out_trade_no'] = '1217752501201407';    //自定义的订单号
     *                    $params['total_fee'] = '100';                    //订单金额 只能为整数 单位为分
     * @return mixed
     */
    public function getAppPaySign($params)
    {
        $result = $this->unifiedOrder($params);
        if ($result['return_code'] == 'SUCCESS' && $result['result_code'] == 'SUCCESS') {
            $data = $this->getAppPayParams($result['prepay_id']);
            return $data;
        } else {
//            $result['return_msg']  注意跟踪失败原因
            $this->errorMsg = $result['return_msg'];
            return false;
        }
    }


    /**
     * 生成签名
     * @return 签名
     */
    public function MakeSign($params)
    {
        //签名步骤一：按字典序排序数组参数
        ksort($params);
        $string = $this->ToUrlParams($params);
        //签名步骤二：在string后加入KEY
        $string = $string . "&key=" . $this->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;
    }

    /**
     * 将参数拼接为url: key=value&key=value
     * @param    $params
     * @return    string
     */
    public function ToUrlParams($params)
    {
        $string = '';
        if (!empty($params)) {
            $array = array();
            foreach ($params as $key => $value) {
                $array[] = $key . '=' . $value;
            }
            $string = implode("&", $array);
        }
        return $string;
    }

    /**
     * 输出xml字符
     * @param    $params        参数名称
     * return    string        返回组装的xml
     **/
    public function data_to_xml($params)
    {
        if (!is_array($params) || count($params) <= 0) {
            return false;
        }
        $xml = "<xml>";
        foreach ($params as $key => $val) {
            if (is_numeric($val)) {
                $xml .= "<" . $key . ">" . $val . "</" . $key . ">";
            } else {
                $xml .= "<" . $key . "><![CDATA[" . $val . "]]></" . $key . ">";
            }
        }
        $xml .= "</xml>";
        return $xml;
    }


    /**
     * 将xml转为array
     * @param string $xml
     * return array
     */
    public function xml_to_data($xml)
    {
        if (!$xml) {
            return false;
        }
        //将XML转为array
        //禁止引用外部xml实体
        libxml_disable_entity_loader(true);
        $data = json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA)), true);
        return $data;
    }


    /**
     * 获取毫秒级别的时间戳
     */
    private static function getMillisecond()
    {
        //获取毫秒的时间戳
        $time = explode(" ", microtime());
        $time = $time[1] . ($time[0] * 1000);
        $time2 = explode(".", $time);
        $time = $time2[0];
        return $time;
    }

    /**
     * 产生一个指定长度的随机字符串,并返回给用户
     * @param type $len 产生字符串的长度
     * @return string 随机字符串
     */
    private function genRandomString($len = 32)
    {
        $chars = array(
            "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k",
            "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v",
            "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G",
            "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R",
            "S", "T", "U", "V", "W", "X", "Y", "Z", "0", "1", "2",
            "3", "4", "5", "6", "7", "8", "9"
        );
        $charsLen = count($chars) - 1;
        // 将数组打乱
        shuffle($chars);
        $output = "";
        for ($i = 0; $i < $len; $i++) {
            $output .= $chars[mt_rand(0, $charsLen)];
        }
        return $output;
    }

    /**
     * 以post方式提交xml到对应的接口url
     *
     * @param string $xml 需要post的xml数据
     * @param string $url url
     * @param bool $useCert 是否需要证书，默认不需要
     * @param int $second url执行超时时间，默认30s
     * @throws WxPayException
     */
    private function postXmlCurl($xml, $url, $useCert = false, $second = 30)
    {
        $ch = curl_init();
        //设置超时
        curl_setopt($ch, CURLOPT_TIMEOUT, $second);

        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
        //设置header
        curl_setopt($ch, CURLOPT_HEADER, FALSE);
        //要求结果为字符串且输出到屏幕上
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);

        if ($useCert == true) {
            //设置证书
            //使用证书：cert 与 key 分别属于两个.pem文件
            curl_setopt($ch, CURLOPT_SSLCERTTYPE, 'PEM');
            //curl_setopt($ch,CURLOPT_SSLCERT, WxPayConfig::SSLCERT_PATH);
            curl_setopt($ch, CURLOPT_SSLKEYTYPE, 'PEM');
            //curl_setopt($ch,CURLOPT_SSLKEY, WxPayConfig::SSLKEY_PATH);
        }
        //post提交方式
        curl_setopt($ch, CURLOPT_POST, TRUE);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
        //运行curl
        $data = curl_exec($ch);
        //返回结果
        if ($data) {
            curl_close($ch);
            return $data;
        } else {
            $error = curl_errno($ch);
            curl_close($ch);
            return false;
        }
    }

    /**
     * 错误代码
     * @param    $code        服务器输出的错误代码
     * return string
     */
    public function error_code($code)
    {
        $errList = array(
            'NOAUTH' => '商户未开通此接口权限',
            'NOTENOUGH' => '用户帐号余额不足',
            'ORDERNOTEXIST' => '订单号不存在',
            'ORDERPAID' => '商户订单已支付，无需重复操作',
            'ORDERCLOSED' => '当前订单已关闭，无法支付',
            'SYSTEMERROR' => '系统错误!系统超时',
            'APPID_NOT_EXIST' => '参数中缺少APPID',
            'MCHID_NOT_EXIST' => '参数中缺少MCHID',
            'APPID_MCHID_NOT_MATCH' => 'appid和mch_id不匹配',
            'LACK_PARAMS' => '缺少必要的请求参数',
            'OUT_TRADE_NO_USED' => '同一笔交易不能多次提交',
            'SIGNERROR' => '参数签名结果不正确',
            'XML_FORMAT_ERROR' => 'XML格式错误',
            'REQUIRE_POST_METHOD' => '未使用post传递参数 ',
            'POST_DATA_EMPTY' => 'post数据不能为空',
            'NOT_UTF8' => '未使用指定编码格式',
        );
        if (array_key_exists($code, $errList)) {
            return $errList[$code];
        }
    }

}

使用案例：

<?php
/**
 * Created by PhpStorm.
 * User: Administrator
 * Date: 2016/12/24 0024
 * Time: 上午 9:33
 */

namespace app\pay\tool;


/**
 * 微信app支付
 * Class WxpayApp
 * @package app\pay\tool
 */
class WxpayApp extends Pay
{
    /**
     * @var WxpayAppSDK
     */
    protected $wxpayAppSDK=null;

    public function __construct()
    {
        $option = config('wxpay_app');
        $notifyurl    = \think\Url::build('WxpayApp/notify', '', true, true);
//        log_debug("微信notifyurl",$notifyurl);
        $option['notify_url'] = $notifyurl;
        $this->wxpayAppSDK = new WxpayAppSDK($option);
    }

    /**
     * 签名客户端
     * @param $order_num
     * @param $sum_pay
     * @param $business_type
     */

    public function sign($order_num, $sum_pay, $business_type){
        $params['body'] = config('pay_title.' . $business_type);                        //商品描述
        $params['out_trade_no'] = $order_num;    //自定义的订单号
        $params['total_fee'] = $sum_pay*100;                    //订单金额 只能为整数 单位为分
        $result=$this->wxpayAppSDK->getAppPaySign($params);
        return $result;
    }

    /**
     * 异步通知
     * @return mixed
     */
    public function notify(){
        $data=$this->wxpayAppSDK->getNotifyData();
//        log_debug("微信app支付回调",json_encode($data));
        if(!$this->wxpayAppSDK->verifyNotify($data)){
            $this->wxpayAppSDK->replyNotifyFail();
//            log_debug("微信app支付回调","签名失败！");
            return;
        }

        $res=$this->updateOrder($data['out_trade_no'],$data['transaction_id'],0,$data['total_fee']/100.00);
        if($res['code']==1){
            $this->wxpayAppSDK->replyNotifySuccess();
        }else{
//            log_debug("微信app支付回调","修改订单状态失败！");
            $this->wxpayAppSDK->replyNotifyFail();
        }

    }

}