The Weird and The Wonderful

public class Controller
{
    //Lots of other methods left out...

    public User getUserByID(String email, long id) throws Exception
    {
        final ObjectHolder<User> userHolder = new ObjectHolder();
        final AtomicBoolean done = new AtomicBoolean(false);

        userBase.handleAction(email, new GetUserByIDAction(), new GetUserByIDActionExecutionDetails(id), new IActionListener<User>()
        {
            @Override
            public void actionFinished(User user) throws Exception
            {
                synchronized (done)
                {
                    userHolder.set(user);
                    done.set(true);
                    done.notifyAll();
                }
            }

            @Override
            public void exception(Exception exception) throws Exception
            {
                synchronized (done)
                {
                    done.set(true);
                    done.notifyAll();
                    throw exception;
                }
            }
        });
        
        synchronized (done)
        {
            while (!done.get()) {
                done.wait(100);
            }

            if (userHolder.get() == null) {
                throw new UserNotFoundException(id);
            } else {
                return userHolder.get();
            }
        }
    }
    
    private class ObjectHolder<T>
    {
        private T t;
        
        public ObjectHolder(T t)
        {
            set(t);
        }
        
        public void set(T t)
        {
            this.t = t;
        }
        
        public T get()
        {
            return t;
        }
    }

}