使用Ajax推送通知

I've searched everywhere for this issue, all I found is same problem but with other programming language, so that didn't help me a lot :(

Now I'm using Hibernate, Struts to develop my web site, when an user connect I should display unread messages. I've developed my own solution, but seems to me very costly here it is:

<script type="text/javascript">
    var auto_refresh = setInterval(
    function ()
    {           
        var url = "<%=request.getContextPath()%>"+"/MessagesRecus.do"; 
        jQuery("#messages").load(url).fadeIn("slow");
    }, 400); //Raffraichir chaque 1 seconde
</script>

MessagesRecus.do : is an action that gets unread messages from the DB

I've learned, while I was looking on the other sites, about push notification system. Does anyone have an idea about it? any other suggestion is welcome :) Thank u in advance.

I can't tell you a specific system. But currently the best solution I think is to use HTML5 websockets. But there are also javascript libraries that support "Ajax Push" or "Comet", like for example JQuery. I think that should point you on the right track.