RE: [soa-rm-ra] OO vs. SOA and what goes into a service

["Poulin, Michael" <Michael.Poulin@uk.fid-intl.com>]

To the Ken's point, service is a model of a function with its features, not a object. So, the function/feature is defined first which can lead to one or many couple of data and behaviour - objects. But, it is an implementation detail.

 

At the concept level, working with services means working with functions. This is why I always was against "simple" exposing of an object via a Web Service interface (very popular approach for service development beginners).

 

However, similarly to an object, a service has its behaviour - business behaviour which is provided by the service body (implementation, if you want), which may be not visible via the service interface. I do have a couple of real-life examples of this.

 

- Michael Poulin

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Fidelity Investments International

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From: Ken Laskey [mailto:klaskey@mitre.org]
Sent: 23 January 2008 03:58
To: Duane Nickull
Cc: soa-rm-ra
Subject: Re: [soa-rm-ra] OO vs. SOA and what goes into a service

I'm not talking implementation (SOA can use OO principles to develop the code) but general mindset.  We once agreed that asking "what is a service?" is similar to asking "what is an object?" because the answer is it could be anything that fits your problem.  My thought is a service is not necessarily a good object that you operate on but more like an operation that you may be feeding objects to.

Again, this is all at the concept level, no implementation.

Ken

On Jan 22, 2008, at 6:45 PM, Duane Nickull wrote:

In SOA, is it necessary that there is an object behind the service?  We talk to the interface (service)and don’t really care what is behind it.  Assuming there is an object could be errant and architecturally un-elegant.

Duane


On 1/22/08 3:05 PM, "Ken Laskey" <klaskey@mitre.org> wrote:

Is it fair (or at least not too distorted) to say that with OO we define an object and look for what we can do to it (i.e. its methods) while with SOA we identify what we want to do (i.e. business functions) and then, if appropriate, look for objects to do it to?

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