微信公众平台开发自动更新微信accesstoken

一、Access Token

access_token是公众号的全局唯一票据，公众号调用各接口时都需使用access_token。正常情况下access_token有效期为7200秒，重复获取将导致上次获取的access_token失效。

公众号可以使用AppID和AppSecret调用本接口来获取access_token。AppID和AppSecret可在开发模式中获得（需要已经成为开发者，且帐号没有异常状态）。注意调用所有微信接口时均需使用https协议。

接口调用请求说明

http请求方式: GET
https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=APPID&secret=APPSECRET

参数说明

返回说明

正常情况下，微信会返回下述JSON数据包给公众号：

{"access_token":"ACCESS_TOKEN","expires_in":7200}

三、实现

class class_weixin
{
    var $appid = APPID;
    var $appsecret = APPSECRET;

    //构造函数，获取Access Token
    public function __construct($appid = NULL, $appsecret = NULL)
    {
        if($appid && $appsecret){
            $this->appid = $appid;
            $this->appsecret = $appsecret;
        }

        //1. 数据库形式
        /*
        DROP TABLE IF EXISTS `wx_token`;
        CREATE TABLE IF NOT EXISTS `wx_token` (
          `id` int(1) NOT NULL,
          `type` varchar(20) NOT NULL,
          `expire` varchar(16) NOT NULL,
          `value` varchar(600) NOT NULL,
          PRIMARY KEY (`id`)
        ) ENGINE=MyISAM DEFAULT CHARSET=utf8;

        INSERT INTO `wx_token` (`id`, `type`, `expire`, `value`) VALUES
        (1, &＃39;access_token&＃39;, &＃39;1425534992&＃39;, &＃39;t3oyW9fRnOWKQHQhZXoEH-pgThhjmnCqTVpaLyUD&＃39;),
        (2, &＃39;jsapi_ticket&＃39;, &＃39;&＃39;, &＃39;&＃39;);
        */
        $con = mysql_connect(MYSQLHOST.&＃39;:&＃39;.MYSQLPORT, MYSQLUSER, MYSQLPASSWORD);
        mysql_select_db(MYSQLDATABASE, $con);
        $result = mysql_query("SELECT * FROM `wx_token` WHERE `type` = &＃39;access_token&＃39;");
        while($row = mysql_fetch_array($result))
        {
            $this->access_token = $row[&＃39;value&＃39;];
            $this->expires_time = $row[&＃39;expire&＃39;];
            break;
        }
        if (time() > ($this->expires_time + 3600)){
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$this->appid."&secret=".$this->appsecret;
            $res = $this->http_request($url);
            $result = json_decode($res, true);
            $this->access_token = $result["access_token"];
            $this->expires_time = time();
            mysql_query("UPDATE `wx_token` SET `expire` = &＃39;$this->expires_time&＃39;, `value` = &＃39;$this->access_token&＃39; WHERE `type` = &＃39;access_token&＃39;;");
        }

        //2. 缓存形式
        if (isset($_SERVER[&＃39;HTTP_APPNAME&＃39;])){        //SAE环境，需要开通memcache
            $mem = memcache_init();
        }else {                                        //本地环境，需已安装memcache
            $mem = new Memcache;
            $mem->connect(&＃39;localhost&＃39;, 11211) or die ("Could not connect");
        }
        $this->access_token = $mem->get($this->appid);
        if (!isset($this->access_token) || empty($this->access_token)){
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$this->appid."&secret=".$this->appsecret;
            $res = $this->http_request($url);
            $result = json_decode($res, true);
            $this->access_token = $result["access_token"];
            $mem->set($this->appid, $this->access_token, 0, 3600);
        }

        //3. 本地写入
        $res = file_get_contents(&＃39;access_token.json&＃39;);
        $result = json_decode($res, true);
        $this->expires_time = $result["expires_time"];
        $this->access_token = $result["access_token"];

        if (time() > ($this->expires_time + 3600)){
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$this->appid."&secret=".$this->appsecret;
            $res = $this->http_request($url);
            $result = json_decode($res, true);
            $this->access_token = $result["access_token"];
            $this->expires_time = time();
            file_put_contents(&＃39;access_token.json&＃39;, &＃39;{"access_token": "&＃39;.$this->access_token.&＃39;", "expires_time": &＃39;.$this->expires_time.&＃39;}&＃39;);
        }

        //4. 实时拉取
        $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$this->appid."&secret=".$this->appsecret;
        $res = $this->http_request($url);
        $result = json_decode($res, true);
        $this->access_token = $result["access_token"];
        $this->expires_time = time();
    }

更多微信公众平台开发自动更新微信access token相关文章请关注PHP中文网！