我使用facebook api在我的网站上收集用户facebook长期访问令牌并将其保存在数据库中。现在我想从数据库中检索它们并在墙上发布。但是我收到以下错误消息：
Facebook SDK返回错误：您必须提供访问令牌。
他们已经给了我必要的权限，我已经从数据库
提供了访问令牌代码：
<?php
define('FACEBOOK_SDK_V4_SRC_DIR', __DIR__.'/src/Facebook/');
require_once(__DIR__.'/src/Facebook/autoload.php');
$fb = new Facebook\Facebook([
'app_id' => '***************',
'app_secret' => '***************',
'default_graph_version' => 'v2.11',
]);
$helper = $fb->getRedirectLoginHelper();
$permissions = ['email','publish_actions','manage_pages','publish_pages'];
// optional
$query = 'SELECT * FROM music_promotion';
$stmt = mysqli_query ($dbc,$query);
while ($row=mysqli_fetch_array($stmt)){
$_SESSION['facebook_access_token'] = $row['fb_access_token'];
try {
if (isset($_SESSION['facebook_access_token'])) {
$accessToken = $_SESSION['facebook_access_token'];
} else {
$accessToken = $helper->getAccessToken();
}
} catch(Facebook\Exceptions\facebookResponseException $e) {
// When Graph returns an error
echo 'Graph returned an error: ' . $e->getMessage();
exit;
} catch(Facebook\Exceptions\FacebookSDKException $e) {
// When validation fails or other local issues
echo 'Facebook SDK returned an error: ' . $e->getMessage();
exit;
}
if (isset($accessToken)) {
if (isset($_SESSION['facebook_access_token'])) {
$fb->setDefaultAccessToken($_SESSION['facebook_access_token']);
} else {
// getting short-lived access token
$_SESSION['facebook_access_token'] = (string) $accessToken;
// OAuth 2.0 client handler
$oAuth2Client = $fb->getOAuth2Client();
// Exchanges a short-lived access token for a long-lived one
$longLivedAccessToken = $oAuth2Client-
>getLongLivedAccessToken($_SESSION['facebook_access_token']);
$_SESSION['facebook_access_token'] = (string) $longLivedAccessToken;
// setting default access token to be used in script
$fb->setDefaultAccessToken($_SESSION['facebook_access_token']);
}
try {
//Post property to Facebook
$linkData = [
'link' => 'the link',
'message' => 'the message'
];
$pageAccessToken = $_SESSION['facebook_access_token'];
try {
$response = $fb->post('/me/feed', $linkData, $pageAccessToken);
} catch(Facebook\Exceptions\FacebookResponseException $e) {
echo 'Graph returned an error: '.$e->getMessage();
exit;
} catch(Facebook\Exceptions\FacebookSDKException $e) {
echo 'Facebook SDK returned an error: '.$e->getMessage();
exit;
}
$graphNode = $response->getGraphNode();
} catch(Facebook\Exceptions\FacebookResponseException $e) {
// When Graph returns an error
echo 'Graph returned an error: ' . $e->getMessage();
session_destroy();
// redirecting user back to app login page
header("Location: ./");
exit;
} catch(Facebook\Exceptions\FacebookSDKException $e) {
// When validation fails or other local issues
echo 'Facebook SDK returned an error: ' . $e->getMessage();
exit;
}
}
}