微信开发-access_token 过期解决方法

微信提供了丰富发的开发接口(如包括自定义菜单接口、客服接口、获取用户信息接口),调用这些接口时需要传入 access_token,它是访问接口的凭证. 但access_token 时效只有7200s , 目前，获取access_token接口的调用频率限制为2000次/天.
如果每次使用接口前先获取一遍access_token,这显然不合理.

解决思路很简单：创建一个xml格式的文件,保存access_token,如果超时则更新.

创建xml文件

<?xml version="1.0" encoding="UTF-8"?>
<access_token_save>
<appid>填写appid</appid>
<appsecret>填写 appsecret</span></appsecret>
<access_token>填写accesstoken</access_token>
<time>填写更新时间戳</time>
</access_token_save>

构建获取access_token 类

class access_token {

private $xml = array();//存储xml文件信息

private $url ='xml文件路径';

/*构造函数*/
function __construct() {

$this->read_xml();

$this->judge_access_token_act();

}

/*读取xml文件*/

private function read_xml() {

$xml = simplexml_load_file($this->url);

foreach ($xml as $k => $v) {

$this->xml[$k] = trim((string)$v);

}

}

/*更新xml文件*/

private function write_xml() {

$xml = simplexml_load_file($this->url);

$xml->time = time();

$xml->access_token = $this->xml['access_token'];

$file = fopen($this->url,"w");

fwrite($file,$xml->asXML());

fclose($file);

}

/*获取access_token*/

private function set_access_token() {

$appid = $this->xml['appid'];

$appsecret = $this->xml['appsecret'];

$url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$appid&secret=$appsecret";

$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);

$output = curl_exec( $ch);

curl_close( $ch);

$jsoninfo = json_decode( $output, true);

$this->xml['access_token'] = $jsoninfo["access_token"];

}

/*判断access_token是否超时*/

private function judge_access_token_act(){

$time = time() - (int)$this->xml['time'];

if($time >= 1800){

$this->set_access_token();

$this->write_xml();

}else{

$this->access_token = $this->xml['access_token'];

}

}

/*获取access_token*/

function __toString() {

return $this->xml['access_token'];

}

}

需要获取acctoken 时调用格式如下
$acc = new access_token();

$access_token = $acc