<?php
class wechatAppPay
{ 
//介面API URL字首
const API_URL_PREFIX = 'https://api.mch.weixin.qq.com';
//下單地址URL
const UNIFIEDORDER_URL = "/pay/unifiedorder";
//查詢訂單URL
const ORDERQUERY_URL = "/pay/orderquery";
//關閉訂單URL
const CLOSEORDER_URL = "/pay/closeorder";
//公眾賬號ID
private $appid;
//商戶號
private $mch_id;
//隨機字串
private $nonce_str;
//簽名
private $sign;
//商品描述
private $body;
//商戶訂單號
private $out_trade_no;
//支付總金額
private $total_fee;
//終端IP
private $spbill_create_ip;
//支付結果回撥通知地址
private $notify_url;
//交易型別
private $trade_type;
//支付金鑰
private $key;
//證書路徑
private $SSLCERT_PATH;
private $SSLKEY_PATH;
//所有引數
private $params = array();
public function __construct($appid, $mch_id, $notify_url, $key)
{
$this->appid = $appid;
$this->mch_id = $mch_id;
$this->notify_url = $notify_url;
$this->key = $key;
}
/**
* 下單方法
* @param $params 下單引數
*/
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 = $params['trade_type'];
$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;
//獲取簽名資料
$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;
}
/**
* 查詢訂單資訊
* @param $out_trade_no 訂單號
* @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;
//獲取簽名資料
$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;
}
/**
* 關閉訂單
* @param $out_trade_no 訂單號
* @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;
//獲取簽名資料
$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;
}
/**
* 
* 獲取支付結果通知資料
* return array
*/
public function getNotifyData(){
//獲取通知的資料
$xml = $GLOBALS['HTTP_RAW_POST_DATA'];
$data = array();
if( empty($xml) ){
return false;
}
$data = $this->xml_to_data( $xml );
if( !empty($data['return_code']) ){
if( $data['return_code'] == 'FAIL' ){
return false;
}
}
return $data;
}
/**
* 接收通知成功後應答輸出XML資料
* @param string $xml
*/
public function replyNotify(){
$data['return_code'] = 'SUCCESS';
$data['return_msg'] = 'OK';
$xml = $this->data_to_xml( $data );
echo $xml;
die();
}
/**
* 生成APP端支付引數
* @param $prepayid 預支付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;
}
/**
* 生成簽名
* @return 簽名
*/
public function MakeSign( $params ){
//簽名步驟一：按字典序排序陣列引數
ksort($params);
$string = $this->ToUrlParams($params);
//簽名步驟二：在string後加入KEY
$string = $string . "&key=".$this->key;
//簽名步驟三：MD5加密
$string = md5($string);
//簽名步驟四：所有字元轉為大寫
$result = strtoupper($string);
return $result;
}
/**
* 將引數拼接為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;
}
/**
* 輸出xml字元
* @param $params 引數名稱
* return string 返回組裝的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; 
}
/**
* 將xml轉為array
* @param string $xml
* return array
*/
public function xml_to_data($xml){ 
if(!$xml){
return false;
}
//將XML轉為array
//禁止引用外部xml實體
libxml_disable_entity_loader(true);
$data = json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA)), true); 
return $data;
}
/**
* 獲取毫秒級別的時間戳
*/
private static function getMillisecond(){
//獲取毫秒的時間戳
$time = explode ( " ", microtime () );
$time = $time[1] . ($time[0] * 1000);
$time2 = explode( ".", $time );
$time = $time2[0];
return $time;
}
/**
* 產生一個指定長度的隨機字串,並返回給使用者 
* @param type $len 產生字串的長度
* @return string 隨機字串
*/
private function genRandomString($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;
// 將陣列打亂 
shuffle($chars);
$output = "";
for ($i = 0; $i < $len; $i++) {
$output .= $chars[mt_rand(0, $charsLen)];
}
return $output;
}
/**
* 以post方式提交xml到對應的介面url
* 
* @param string $xml 需要post的xml資料
* @param string $url url
* @param bool $useCert 是否需要證書，預設不需要
* @param int $second url執行超時時間，預設30s
* @throws WxPayException
*/
private function postXmlCurl($xml, $url, $useCert = false, $second = 30){ 
$ch = curl_init();
//設定超時
curl_setopt($ch, CURLOPT_TIMEOUT, $second);
curl_setopt($ch,CURLOPT_URL, $url);
curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,FALSE);
curl_setopt($ch,CURLOPT_SSL_VERIFYHOST,2);
//設定header
curl_setopt($ch, CURLOPT_HEADER, FALSE);
//要求結果為字串且輸出到螢幕上
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
if($useCert == true){
//設定證書
//使用證書：cert 與 key 分別屬於兩個.pem檔案
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);
//執行curl
$data = curl_exec($ch);
//返回結果
if($data){
curl_close($ch);
return $data;
} else { 
$error = curl_errno($ch);
curl_close($ch);
return false;
}
}
/**
* 錯誤程式碼
* @param $code 伺服器輸出的錯誤程式碼
* return string
*/
public function error_code( $code ){
$errList = array(
'NOAUTH' => '商戶未開通此介面許可權',
'NOTENOUGH' => '使用者帳號餘額不足',
'ORDERNOTEXIST' => '訂單號不存在',
'ORDERPAID' => '商戶訂單已支付，無需重複操作',
'ORDERCLOSED' => '當前訂單已關閉，無法支付',
'SYSTEMERROR' => '系統錯誤!系統超時',
'APPID_NOT_EXIST' => '引數中缺少APPID',
'MCHID_NOT_EXIST' => '引數中缺少MCHID',
'APPID_MCHID_NOT_MATCH' => 'appid和mch_id不匹配',
'LACK_PARAMS' => '缺少必要的請求引數',
'OUT_TRADE_NO_USED' => '同一筆交易不能多次提交',
'SIGNERROR' => '引數簽名結果不正確',
'XML_FORMAT_ERROR' => 'XML格式錯誤',
'REQUIRE_POST_METHOD' => '未使用post傳遞引數 ',
'POST_DATA_EMPTY' => 'post資料不能為空',
'NOT_UTF8' => '未使用指定編碼格式',
); 
if( array_key_exists( $code , $errList ) ){
return $errList[$code];
}
}
}

使用的方法

<?php
include 'wechatAppPay.class.php';
//1.統一下單方法
$wechatAppPay = new wechatAppPay($appid, $mch_id, $notify_url, $key);
$params['body'] = '商品描述'; //商品描述
$params['out_trade_no'] = 'O20160617021323-001'; //自定義的訂單號
$params['total_fee'] = '100'; //訂單金額 只能為整數 單位為分
$params['trade_type'] = 'APP'; //交易型別 JSAPI | NATIVE | APP | WAP 
$result = $wechatAppPay->unifiedOrder( $params );
print_r($result); // result中就是返回的各種資訊資訊，成功的情況下也包含很重要的prepay_id
//2.建立APP端預支付引數
/** @var TYPE_NAME $result */
$data = @$wechatAppPay->getAppPayParams( $result['prepay_id'] );
// 根據上行取得的支付引數請求支付即可
print_r($data);
?>