Facebook PHP 使用 cronjob 发布到粉丝页面?

I am using the following code to post to my facebook fan page and it is working fine. Now I want to use cronjob in order to post to Facebook. I know I have to use as access token but I am not sure how to set it up. I tried to use echo my own access token and the page's access token and use it in the post api but that did not work I got this error:

Uncaught OAuthException: An active access token must be used to query information about the current user.

这是我尝试过的代码:

require_once('scripts/facebook.php');
    $config = array('appId' => 'xxx','secret' => 'xxx');

    $params = array('scope'=>'user_likes,publish_actions,email,offline_access,publish_stream,manage_pages');
    $facebook = new Facebook($config);
    $user = $facebook->getUser();
    if($facebook->getUser()) {
    try {

        $user_profile = $facebook->api('/me');
        $access_token = $facebook->getAccessToken();
        //echo "1. ".$access_token;

      } catch(FacebookApiException $e) {
                        $login_url = $facebook->getLoginUrl($params);
                        error_log($e->getType());
                        error_log($e->getMessage());
      }   
    } else {
        $login_url = $facebook->getLoginUrl($params);

    }    

$page_id = "xxxxxxxxxxxxx";
            $page_access_token = "";
            $result = $facebook->api("/me/accounts");
            foreach($result["data"] as $page) {
                if($page["id"] == $page_id) {
                $page_access_token = $page["access_token"];
                //echo '<br>';
                //echo "2. ".$page_access_token;
                break;
                    }
                }


        $args = array(
            'access_token'  => 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
            'message'       => stripslashes($image_caption).$animaged_gif,
            'name' => stripslashes($image_caption).$animaged_gif,
            'link' => "http://www.example.com/images.php?i=".$image_name,
            'picture' => "http://www.example.com/thumbnails/".$image_name.".png",
            'actions' => array(
            'name' => 'See Pic',
            'link' => "http://www.example.com/images.php?i=".$image_name
            )

        );
       $post = $facebook->api("/$page_id/feed","post",$args);

如您所见，我尝试使用我在回显自己的访问令牌时获得的实际访问令牌.但这没有用.我还使用了页面的访问令牌，但这也不起作用.你能告诉我我在这里遗漏了什么，或者这样做的正确方法是什么?经过进一步的搜索，我发现了 setAccessToken 和 $page_info = $fb->api("/".$sInfo['pageId']."?fields=access_token"); 但是关于如何使用它们的资源非常有限.我什至不确定这些是否适合这个问题.我只需要知道我需要使用哪个访问令牌以及设置它的适当代码是什么?

<?php

//read more : https://developers.facebook.com/docs/howtos/login/server-side-login/
session_start();
$app_id = "xxxxxxxxxxxxxx";
$app_secret = "xxxxxxxxxxxxxxxx";
$my_url = "www.stackoverflow.com/";  // redirect url

$code = $_REQUEST["code"];

if(empty($code)) {
    // Redirect to Login Dialog
    $_SESSION['state'] = md5(uniqid(rand(), TRUE)); // CSRF protection
    $dialog_url = "https://www.facebook.com/dialog/oauth?client_id=" 
       . $app_id . "&redirect_uri=" . urlencode($my_url) . "&state="
       . $_SESSION['state'] . "&scope=publish_stream,read_friendlists,email";


    echo("<script> top.location.href='" . $dialog_url . "'</script>");
}
if($_SESSION['state'] && ($_SESSION['state'] === $_REQUEST['state'])) {
    $token_url = "https://graph.facebook.com/oauth/access_token?"
       . "client_id=" . $app_id . "&redirect_uri=" . urlencode($my_url)
       . "&client_secret=" . $app_secret . "&code=" . $code;

     $response = file_get_contents($token_url);
     $params = null;
     parse_str($response, $params);
     $longtoken=$params['access_token'];


//save it to database   
} 
?>

<?
require_once('scripts/facebook.php');
// Pull access token from the file/db
$access_token = "access token from file or db";
$facebook->setAccessToken($access_token); // sets our access token as the access token when we call something using the SDK, which we are going to do now.

$config = array('appId' => 'xxx','secret' => 'xxx');

$params = array('scope'=>'user_likes,publish_actions,email,publish_stream,manage_pages');
$facebook = new Facebook($config);
$user = $facebook->getUser();
if($facebook->getUser()) {
    try {

        $user_profile = $facebook->api('/me');
    } catch(FacebookApiException $e) {
        $login_url = $facebook->getLoginUrl($params);
        error_log($e->getType());
        error_log($e->getMessage());
    }   
}
else {
    $login_url = $facebook->getLoginUrl($params);
}    

$page_id = "xxxxxxxxxxxxx";
$page_access_token = "";
$result = $facebook->api("/me/accounts");
foreach($result["data"] as $page) {
    if($page["id"] == $page_id) {
        $page_access_token = $page["access_token"];
        //echo '<br>';
        //echo "2. ".$page_access_token;
        break;
    }
}

$args = array(
    'access_token'  => $page_access_token,
    'message'       => stripslashes($image_caption).$animaged_gif,
    'name' => stripslashes($image_caption).$animaged_gif,
    'link' => "http://www.example.com/images.php?i=".$image_name,
    'picture' => "http://www.example.com/thumbnails/".$image_name.".png",
    'actions' => array(
            'name' => 'See Pic',
             'link' => "http://www.example.com/images.php?i=".$image_name
    )
);
$post = $facebook->api("/$page_id/feed","post",$args);
?>