Asynchronous Servlet Client, Server push

Hello guys i want to process some server pushes. I have an asynchronous servlet processing something, pushing it to the client and then it processes something else and pushes it again to the client (same connection). The servet just returns data (Json in this case, but that does not really mather) nothing more.

So my problem is the client. How do i build a client for that? If i make an ajax request with JQuery for example how can i react on the data that comes after the first response?

To make it more clear what i want here is a comparison : With websockets i have the method onmesssage.

websocket ws = new WebSocket("ws://myserver.com");
ws.onmessage = function(event)
{
   var x = event.dat开发者_运维百科a
   .... // some other code here
}

So all i want is a onmessage Method :). I guess it is not that easy as it is with websockets but maybe someone has an idea.

Greetings Aleks

You can have your server generate a response which is loaded into an hidden iframe by the client. The generated response would contain occasional JavaScript statements which call to the "outside" (the containing document). You can get your hands on the containing document using parent.

But please not that this technique is pretty hackish (at least it seems to me). You might want to re-consider just using the XMLHttpRequest, especially because it gives you simple and robust error handling. You can just do more requests (instead of appending to an "old" response on the server side). This will probably introduce additional lag, but that iframe trick is really troublesome in practice.