Robin wrote: > Hi Murray, I do not agree with you. > I do not think code mobility violates service-orientation.
> --- In [email protected], "Spork, > Murray" <[EMAIL PROTECTED]> wrote: > > This is also BTW the reason why code mobility violates > > service-orientation IMO - because the notion of provision *by someone > > else* is removed. [cue Greg ;-)] That is not to say code mobility is not > > useful in some cases - but for me the provision aspect is central to the > > concerns that service-orientation seeks to address. I was just going to let this one be, but Robin's response drove me to a position of supporting his response with an example. This is an interesting issue. With Jini, it's ConfigurationFile mechanism, and the Exporter mechanism, you could actually package the use of a smart proxy into a "deployment time" use decision independent of the service implementation and without vendor development support. The technique is fairly simple. You would create the smart proxy that implements the service interface in the way that you want to provide as an optional deployment. The constructor of that smart proxy would accept an instance of the service (implementation of the service interfaces) as the argument. The custom Exporter would then accept the original service as its argument, export the service, create a new instance of the smart proxy, passing in the exported service's proxy and then return the smart proxy. This is the delegate pattern. I'll skip out on providing the the actual code/configuration since this isn't a coding forum, but it's a trivial bit of stuff. This technique, through the use of Class.forName(), could be generalized into a reusable mechanism for any smartproxy substitution into any service in your SOA. You could then create deployment tools specific to this mechanism and allow the deployers free reign over the configuration processes at deployment. It's really not a big deal to do this with Jini/Java. Gregg Wonderly Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/service-orientated-architecture/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
