php Facebook SDK名称空间错误

Question

I am trying to get the new facebook php sdk setup on my site. I'm running the latest stable version of php. I have never messed with namespaces before. Can someone tell me what I'm doing wrong?

I get this error

Fatal error: Class 'FacebookSession' not found in

When I run this code

FacebookSession::setDefaultApplication( 'xxx','yyy' );

.....

// path of these files have changes
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/HttpClients/FacebookHttpable.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/HttpClients/FacebookCurl.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/HttpClients/FacebookCurlHttpClient.php' );

// other files remain the same
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/FacebookSession.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/FacebookRedirectLoginHelper.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/FacebookRequest.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/FacebookResponse.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/FacebookSDKException.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/FacebookRequestException.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/FacebookOtherException.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/FacebookAuthorizationException.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/GraphObject.php' );
require_once( '/var/www/vhosts/server/site/lib/fb/Facebook/GraphSessionInfo.php' );

// path of these files have changes
use Facebook\HttpClients\FacebookHttpable;
use Facebook\HttpClients\FacebookCurl;
use Facebook\HttpClients\FacebookCurlHttpClient;

use Facebook\FacebookSession;
use Facebook\FacebookRedirectLoginHelper;
use Facebook\FacebookRequest;
use Facebook\FacebookResponse;
use Facebook\FacebookSDKException;
use Facebook\FacebookRequestException;
use Facebook\FacebookOtherException;
use Facebook\FacebookAuthorizationException;
use Facebook\GraphObject;
use Facebook\GraphSessionInfo;

Answer 1

Problem was due to PEAR being installed on the server for email. The include path in php settings was modified.

I actually removed PEAR, set PHP back to it's default include path and switched email to swiftmailer.