RE: Why seleton and are web service push technology?

[Mike Oliver]

Michael Oliver AppsAsPeers LLC 7391 S. Bullrider Ave. Tucson, AZ 85747 Phone:(520)574-1150 Fax:(520)844-1036   -----Original Message----- From: Ricky Ho [mailto:[EMAIL PROTECTED]] Sent: Monday, November 11, 2002 11:40 AM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: Re: Why seleton and are web service push technology?   At 11:20 AM 11/11/2002 +0100, niksa_os wrote: 1) For what reason skeleton classes exist, I mean the ability to generate this classes? If I have java class I use axis and make wsdl and client stub. Why skeleton classes? You are suggesting a "dangerous" approach where you generate WSDL from existing Java classes.  Although most popular examples most web service tools vendor gives following this pattern, this is not the right approach. The right approach is to start with WSDL first without worrying about your legacy backend implementation.  After that, you need an adaptor to talk your legacy backend.  The "skeleton class" serves the role as the adaptor. [Mike Oliver>>] I completely concur the Skeleton is a much safer and more easily maintained approach. 2) Are web service push technology  or does it can be? I make web service client and I want that client get new data whenever data change at the server. This can be done with web service? If not, how this can be done? I can't manage server, I can only get data. The client need to have a local server running that can accept the callback.  In other words, during the callback, the roles has turn, the event source (which is the original server) becomes the client and the original client becomes the server.  This is a very common pub/sub scenario.  The client register its interests (together with a callback address) to the server.  When the event occur, the server callback the client via the callback address.     [Mike Oliver>>] Ricky,  that’s fine when you have relative peers, but what about lightweight clients (pda’s, etc.)  to web services?  There the option is polling (ARG!) or some sort of lightweight listener that doesn’t need the full Web Services engine, and only listens for when to be told to call back to the web services for updated data.  Depending on what you are doing that can be as easy as an Applet or an RMI server or even a UDP socket listener, all are typically lighter than servlets or web services. Rgds, Ricky