php微信2 获取自定义菜单中的access_token

//自定义菜单中获取access_token
static function get_access_token($appid,$secret){
$url="https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$appid."&secret=".$secret;
$json=self::http_request_json($url);//这个地方不能用file_get_contents
$data=json_decode($json,true);
if($data['access_token']){
return $data['access_token'];
}else{
return "获取access_token错误";
}
}
//因为url是https 所有请求不能用file_get_contents,用curl请求json 数据
function http_request_json($url){
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$result = curl_exec($ch);
curl_close($ch);
return $result;
}