"IcedCrow" <ch********@aol.com> wrote in message
news:04****************************@phx.gbl...
#1) Burning question on my mind is ... what is the
difference between a "web service" and a distributed COM
component
[....] What's the difference?
Both are, in fact, technologies you can use to build distributed
applications. Therefore they are similar from a 10000 ft perspective.
The differences are:
a) Micrsoft doesn't own the SOAP spec, like it did with DCOM. The SOAP spec
is published and under control of the W3C. Anybody is free to implement it
and thus allow for interoperability between arbitrary platforms. While there
are bridges and inplementations of DCOM on platforms other than windows,
DCOM is very much a Windows technology.
b) Web Services (the SOAP protocol, specifically) are designed for
interoperability. DCOM was in theory, but not in practice.
c) DCOM transmitted data in a binary format, Web services use XML
d) THe SOAP protocol, i.e. Web services are not tied to any particular
transport. You can use SOAP over HTTP, SMTP, MSMQ or whatever suits your
needs. In .NET as it is today, Web services are pretty much to HTTP. The
..NET Framework with the SoapFormatter, the XmlSerializer and WSE allow to
use SOAP over any transport you need.
I am sure there are more, but these come to mind right now.
#2) Question concerning the difference between .NET
remoting and Web services. I read that the .NET remoting
provides the infrastructure to support object remoting
solutions, to include functionality and that Web Services
support only the transport of data and NOT functionality?
Remoting provides full type fidelity for the objects you call methods on the
object you transmit. i.e. if you transmit an object by value from the server
to the client, the client must have the very same implementation of the
class that's available on the server. You can circumvent this by
transferring only interface types and not class types (or write a code to
map between types on the server and the client). Still the client needs to
be able to locate a compatible version of the interface definition. Web
services simply publish an interface using WSDL. This, again, is much like
the publishing an interface derfinition using IDL in DCOM.
--
HTH
Christoph Schittko [MVP]
Software Architect, .NET Mentor