微信access_token全局缓存,处理过期

 //PHP创建access_token.json文件,将access_token 和 生成时间expires 保存在其中,
 //{"access_token":"xxxx","expires":1478799661}
 function getToken(){
     $appid='*';
     $appsecret='**';
     $file = file_get_contents("./access_token.json",true);
     $result = json_decode($file,true);
     echo $time();
 if (time() > $result['expires']){
         $data = array();
         $data['access_token'] = getNewToken($appid,$appsecret);
         $data['expires']=time()+7000;
         $jsonStr =  json_encode($data);
         $fp = fopen("./access_token.json", "w");
         fwrite($fp, $jsonStr);
         fclose($fp);
         return $data['access_token'];
     }else{
         return $result['access_token'];
     }
 }
 function getNewToken($appid,$appsecret){
     $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={$appid}&secret={$appsecret}";
     $access_token_Arr =  https_request($url);
     return $access_token_Arr['access_token'];
 }
 function https_request ($url){
         $ch = curl_init();
         curl_setopt($ch, CURLOPT_URL, $url);
         curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
         curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
         $out = curl_exec($ch);
         curl_close($ch);
         return  json_decode($out,true);
 }
 echo getToken();