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.
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.
Rgds, Ricky
