class Test extends CI_Controller{

    public function index(){
        echo "hello world";
    }

    //index.php/Test/success/id/1aa
    public function _remap($method,$params){
        if($method==‘success‘){
            $method .= ‘2‘; 
            return call_user_func_array(array($this, $method), $params);
        }else{
            $this->index();
        }
    }

    public function success2($id,$key){
        var_dump($id);
        var_dump($key);
    }
}