function getToken(){

    $appid='你的appid';

    $appsecret='你的appsecret';

    $file = file_get_contents("./access_token.json",true);

    $result = json_decode($file,true);

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);

}