yii2 php namespace 引入第三方非namespace库文件时候，报错：Class not found 的解决

一个类文件时namespace的库方式

通过下面的方式引入类,报错 Class Not Found：

namespace frontend/block/customer/account;use Yii;use frontend/block/Blockbase;//use yii/base/Model;//use backend/models/helper/Base.phpuse frontend/models/core/Request;use frontend/models/core/Customer;use frontend/models/core/User;use frontend/models/core/Url;use frontend/models/core/Func;use frontend/models/core/Email;use frontend/models/core/Help;use frontend/models/core/Session;use frontend/models/core/Config;use frontend/models/core/Store;use frontend/models/core/Message;use frontend/models/core/Date;use frontend/models/core/Mongodb;use Facebook/FacebookSession;use Facebook/FacebookRedirectLoginHelper;use Facebook/FacebookRequest;use Facebook/FacebookResponse;use Facebook/FacebookSDKException;use Facebook/FacebookRequestException;use Facebook/FacebookAuthorizationException;use Facebook/GraphObject;use Facebook/Entities/AccessToken;use Facebook/HttpClients/FacebookCurlHttpClient;use Facebook/HttpClients/FacebookHttpable;class Login extends Blockbase{   public function getGoogleLoginUrl(){        $lib_google_base = Yii::getAlias("@common/lib/google");        //echo $lib_google_base.'/Social.php';exit;        $lib_google_base = Yii::getAlias("@common/lib/google");        include $lib_google_base.'/Social.php';        $Social_obj= new Social();        $url = $Social_obj->google();        return $url;    }}

$Social_obj= new /Social();