微信公众平台开发教程②微信端分享功能图文详(4)

<?php
class JSSDK {
 private $appId;
 private $appSecret;

 public function __construct($appId, $appSecret) {
 $this->appId = $appId;
 $this->appSecret = $appSecret;
 }

 public function getSignPackage() {
 $jsapiTicket = $this->getJsApiTicket();

 // 注意 URL 一定要动态获取，不能 hardcode.
 $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
 $url = "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";

 $timestamp = time();
 $nonceStr = $this->createNonceStr();

 // 这里参数的顺序要按照 key 值 ASCII 码升序排序
 $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr×tamp=$timestamp&url=$url";

 $signature = sha1($string);

 $signPackage = array(
 "appId" => $this->appId,
 "jsapiTicket" => $jsapiTicket,
 "nonceStr" => $nonceStr,
 "timestamp" => $timestamp,
 "url" => $url,
 "signature" => $signature,
 "rawString" => $string
 );
 return $signPackage;
 }

 private function createNonceStr($length = 16) {
 $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
 $str = "";
 for ($i = 0; $i < $length; $i++) {
 $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
 }
 return $str;
 }

 private function getJsApiTicket() {
 // jsapi_ticket 应该全局存储与更新，以下代码以写入到文件中做示例
 $data = json_decode($this->get_php_file("jsapi_ticket.php"));
 if ($data->expire_time < time()) {
 $accessToken = $this->getAccessToken();
 // 如果是企业号用以下 URL 获取 ticket
 // $url = "https://qyapi.weixin.qq.com/cgi-bin/get_jsapi_ticket?access_token=$accessToken";
 $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
 $res = json_decode($this->httpGet($url));
 $ticket = $res->ticket;
 if ($ticket) {
 $data->expire_time = time() + 7000;
 $data->jsapi_ticket = $ticket;
 $this->set_php_file("jsapi_ticket.php", json_encode($data));
 }
 } else {
 $ticket = $data->jsapi_ticket;
 }

 return $ticket;
 }

 private function getAccessToken() {
 // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
 $data = json_decode($this->get_php_file("access_token.php"));
 if ($data->expire_time < time()) {
 // 如果是企业号用以下URL获取access_token
 // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
 $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
 $res = json_decode($this->httpGet($url));
 $access_token = $res->access_token;
 if ($access_token) {
 $data->expire_time = time() + 7000;
 $data->access_token = $access_token;
 $this->set_php_file("access_token.php", json_encode($data));
 }
 } else {
 $access_token = $data->access_token;
 }
 return $access_token;
 }

 private function httpGet($url) {
 $curl = curl_init();
 curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
 curl_setopt($curl, CURLOPT_TIMEOUT, 500);
 // 为保证第三方服务器与微信服务器之间数据传输的安全性，所有微信接口采用https方式调用，必须使用下面2行代码打开ssl安全校验。
 // 如果在部署过程中代码在此处验证失败，请到 http://curl.haxx.se/ca/cacert.pem 下载新的证书判别文件。
 curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, true);
 //curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, true);
 curl_setopt($curl, CURLOPT_URL, $url);

 $res = curl_exec($curl);
 curl_close($curl);

 return $res;
 }

 private function get_php_file($filename) {
 return trim(substr(file_get_contents($filename), 15));
 }
 private function set_php_file($filename, $content) {
 $fp = fopen($filename, "w");
 fwrite($fp, "<?php exit();?>" . $content);
 fclose($fp);
 }
}