Question

I need to send a simple message to server which based on gwt. As we know, in payload of the message is the strong hash name of serialization policy file of service we want to send message.
Where, in server-client communication, can I get this hash?
Web browser does it, I was analyzing by fiddler, of firebug comunication, and I didn’t saw any message from server with this hash. So, how the client’s web browser know, which strong hash name send in payload of the message to the service?

Answer 1

It’s hard-coded in the generated JS, and the way the client communicates to the server what version of the service it uses.

With GWT-RPC, the client and server must be in sync (though technically I think you can support several versions of your service –as known by the clients– at the same time), and this is how they check it: the client says “here’s how I know how to talk to you” and the server first checks if it’s OK for it (loads the serialization policy) and either proceed or immediately fail with an IncompatibleRemoteServiceException.
So it’s effectively never sent by the server (well, in the JS code yes, but now through RPC).