如何用php检查验证mongodb id

i get mongodb id of query string. how to check validation this id? i want if mongodb id not valid redirect to another url

get query string:

    if(count($_GET)>0 && $_GET['uid']){

            //get id from string query
            $query = array("_id" => new MongoId($_GET

['uid']));
        $user = DB::findone('users',$query);

    }else{
        //redirect if not exist query string
        header('location:'.ADMIN_URL.'/items/forbidden.php');
    }  

plz help... thanks

In new PHP Mongo library https://github.com/mongodb/mongo-php-library the best way to check validity of a string is: (thanks to Yii2 code https://github.com/yiisoft/yii2-mongodb/blob/master/validators/MongoIdValidator.php)

   function isValid($value)
    {
        if ($value instanceof \MongoDB\BSON\ObjectID) {
            return true;
        }
        try {
            new \MongoDB\BSON\ObjectID($value);
            return true;
        } catch (\Exception $e) {
            return false;
        }
    }

Since ext-mongo version 1.5 you can check it

if(isset($_GET['uid']) && MongoId::isValid ($_GET['uid'])) { 
 // Your code here 
}

php.net mongoid.isvalid