I'm using cakephp and phpwhois I'm copying phpwhois folder in app/vendor in my controller :
App::import('Vendor', 'phpWhois\Whois', array('file' => 'phpWhois/Whois.php'));
whois class is extended with whpisclient class and show me this error :
Error: Class 'phpWhois\WhoisClient' not found
File: C:\xampp\htdocs\padweb\app\Vendor\phpWhois\Whois.php
If I use composer autoloader, it shows me the same error.
see this nice article http://ceeram.github.io/blog/2013/02/22/using-composer-with-cakephp-2-dot-x/ about using composer in cakephp 2.0 it will allow you to use a global autoload.php file for all your new packages that you install with composer
let me know if it helps