微信公众号开发access_token存储到session里面

代码：

<?php
session_start();
if(isset($_SESSION['access_token'])){
    if($_SESSION['expire_time']<time()){
        $access_token = $_SESSION['access_token'];
    }else{
        $access_token = get_access_token();
    }
}else{
    $access_token = get_access_token();
}

function get_access_token(){
    $appid = 'wx5a26ecf684330de4';
    $appsecret = 'bbecbdffb2d167163dac8d764bfbb30b';
    $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$appid&secret=$appsecret";
    $output = https_request($url);
    $jsoninfo = json_decode($output, true);
    $_SESSION['access_token'] = $jsoninfo['access_token'];
    $_SESSION['expire_time'] = time() + 7000;
    return $jsoninfo['access_token'];
}
/**
 * token 有效期7200秒=2小时
 */
// $access_token = "70_hyvVzhqz_6CDWR4YuycdDVbSnvPgcy3-Y6n-8chgofP-jIkGFUf64w87TvbsQs1-BWvIvMk0yQSt13c2RzqbQJ8UfrqHHW5fcq0f5s8T8bSOjwr0nIh9y5cOl90BYUcABAROK";
/**
 * curl请求函数
 */
function https_request($url, $data = null)
{
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);
    if (!empty($data)){
        curl_setopt($curl, CURLOPT_POST, 1);
        curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
    }
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    $output = curl_exec($curl);
    curl_close($curl);
    return $output;
}

function logger($log_content, $type = '用户')
    {
        $max_size = 3000;
        $log_filename = "./log.xml";
        if (file_exists($log_filename) and (abs(filesize($log_filename)) >
                $max_size)) {
            unlink($log_filename);
        }
        file_put_contents($log_filename, "$type  ".date('Y-m-d H:i:s')."\n\r".$log_content."\n\r",
            FILE_APPEND);
    }