AsyncListener.onComplete() not called if AsyncContext.dispatch() is called

protected void doGet(HttpServletRequest req, HttpServletResponse resp) 
{     
        final AsyncContext asyncContext = req.startAsync();
        asyncContext.addListener(new AsyncListener()
        {
            @Override
            public void onComplete(AsyncEvent event) throws IOException
            {
                System.out.println("complete");
            }

            @Override
            public void onTimeout(AsyncEvent event) throws IOException
            {
                System.out.println("timeout");

            }

            @Override
            public void onError(AsyncEvent event) throws IOException
            {
                System.out.println("err");

            }

            @Override
            public void onStartAsync(AsyncEvent event) throws IOException
            {
                System.out.println("start");
            }
        });

        new Thread(new Runnable()
        {
            @Override
            public void run()
            {
                try
                {
                    Thread.sleep(2000);
                    asyncContext.dispatch("/path2");
                } catch (InterruptedException e)
                {
                    e.printStackTrace();
                }
            }
        }).start();

    }