Groups > comp.lang.java.programmer > #20837

Re: Java servlet on browsers: dying or kicking ?

From	Arved Sandstrom <asandstrom2@eastlink.ca>
Newsgroups	comp.lang.java.programmer
Subject	Re: Java servlet on browsers: dying or kicking ?
References	(7 earlier) <50de2260$0$293$14726298@news.sunsite.dk> <JfBDs.90567$2v.68591@newsfe05.iad> <idGdnWAQLIUadEPNnZ2dnUVZ7sudnZ2d@bt.com> <50df9ef7$0$284$14726298@news.sunsite.dk> <jOqdnTE_e8PGgn3NnZ2dnUVZ8uydnZ2d@bt.com>
Message-ID	<5BpEs.20481$tK1.2200@newsfe07.iad> (permalink)
Organization	Public Usenet Newsgroup Access
Date	2012-12-31 19:54 -0400

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On 12/30/2012 07:02 AM, lipska the kat wrote:
> On 30/12/12 01:54, Arne Vajhøj wrote:
>> On 12/29/2012 8:00 AM, lipska the kat wrote:
>>> I see the _service layer_ as aggregating fine grained business methods
>>> behind a facade. The facade then exposes what are in effect 'atomic'
>>> services that implement a particular subset of the business as seen by
>>> the outside world. As far as external clients are concerned the
>>> interface to the business is clearly defined.
>>
>> Facade pattern
>
> Your point being ?
>
>>> My question is how can the orchestration of service layer services
>>> outside the system boundary be controlled in a way that would be
>>> guaranteed not to potentially break the [business] rules ?
>>
>> You need to have context. Either have client send all
>> context or send a ref to context saved in service layer.
>
> Unconvinced I'm afraid
>
> There are two possible types of actor interaction with a business
> Stateless and statefull.
>
> A stateless interaction for example might be a request for currency
> conversion, or a free ESTIMATE for goods or services. You may offer
> these alongside other free services, Clients can mix and match your
> stateless services all they want and it has no impact on your business.
>
> The other type is statefull. These interactions  do impact the state of
> your business, In 20 odd years of designing and implementing business
> systems I have never come across a situation where a business is happy
> to allow it's clients to dictate the terms of business in a random and
> uncontrollable way. Any control exercised over the combination of
> statefull services effectively extends the system boundary so the whole
> argument (allowing external orchestration of services) becomes moot.
>
> This is not some academic conjecture on my part but hard experience in
> the real world.
>
> I'd be interested to hear what the original responder has to say about
> this.
>
> lipska
>
How to classify orchestration - what layer to put it in, in whatever 
architectural model you've selected - or whether even to use the term 
"orchestration" (and by implication to define an orchestration layer), 
really needs to be established up front.

I like using Fowler's model because it's pretty neat, and it's 
reasonably applicable to both SOA and non-SOA. Without getting religious 
about it, if I were to assign orchestration a place in Fowler's diagram, 
I'd have to amend slightly what I said in my previous email in this 
sub-thread, and consider that the process services that make up the 
orchestration layer are also in the Service/Application layer.

To put it another way, if you have true services being made available 
(and I actually agree with your description of them as "'atomic' 
services that implement a particular subset of the business"), then the 
"stitching together" of them that I alluded to is also in the 
Service/Application layer. The lower-level more granular services are 
solution-agnostic; the process services are particular to a given solution.

So to touch on your observation, yes, the system boundary (the 
application boundary) includes the business logic embodied in process 
services (workflow etc).

One other comment - I myself probably wouldn't much use the terms 
"stateless" and "stateful" at all in this particular discussion. If you 
did have a process that combined a number of services, the odds are 
pretty good that each individual service would be stateless, that the 
process itself would have interaction state, and it would be completely 
another issue as to whether this process eventually effected any changes 
in business data (state) or not.

AHS

Thread

Java servlet on browsers: dying or kicking ? "SL@maxis" <noreply@my-rialto.com> - 2012-12-25 01:04 +0800
  Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-24 12:37 -0500
    Re: Java servlet on browsers: dying or kicking ? "SL@maxis" <ecp_gen@my-rialto.com> - 2012-12-25 04:32 +0800
      Re: Java servlet on browsers: dying or kicking ? Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2012-12-26 23:20 -0800
        Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-27 21:05 -0500
        Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-27 21:07 -0500
          Re: Java servlet on browsers: dying or kicking ? Gene Wirchenko <genew@telus.net> - 2012-12-27 21:13 -0800
            Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-28 11:07 -0500
              Re: Java servlet on browsers: dying or kicking ? Gene Wirchenko <genew@telus.net> - 2012-12-28 09:14 -0800
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-28 18:18 -0500
          Re: Java servlet on browsers: dying or kicking ? Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2012-12-28 00:41 -0800
            Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-28 11:14 -0500
            Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-28 17:50 +0000
              Re: Java servlet on browsers: dying or kicking ? Robert Klemme <shortcutter@googlemail.com> - 2012-12-28 21:22 +0100
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-28 21:08 +0000
                Re: Java servlet on browsers: dying or kicking ? Robert Klemme <shortcutter@googlemail.com> - 2012-12-28 22:55 +0100
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-28 18:02 -0500
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-29 08:55 +0000
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-29 20:40 -0500
                Re: Java servlet on browsers: dying or kicking ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2012-12-31 20:08 -0400
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-31 19:33 -0500
              Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-28 17:51 -0500
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-29 11:37 +0000
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-29 11:39 +0000
                Re: Java servlet on browsers: dying or kicking ? Gene Wirchenko <genew@telus.net> - 2012-12-29 22:22 -0800
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-29 20:34 -0500
                Re: Java servlet on browsers: dying or kicking ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2012-12-29 08:22 -0400
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-29 13:00 +0000
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-29 20:54 -0500
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-30 11:02 +0000
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-30 20:33 -0500
                Re: Java servlet on browsers: dying or kicking ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2012-12-31 19:54 -0400
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-29 20:43 -0500
                Re: Java servlet on browsers: dying or kicking ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2012-12-31 19:06 -0400
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-31 19:29 -0500
                Re: Java servlet on browsers: dying or kicking ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-01-01 01:46 +0000
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2012-12-31 21:35 -0500
                Re: Java servlet on browsers: dying or kicking ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-01-01 09:22 -0400
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-04 19:46 -0500
                Re: Java servlet on browsers: dying or kicking ? "Richard Maher" <maher_rj@hotspamnotmail.com> - 2013-01-05 08:22 +0800
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-04 19:59 -0500
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-04 20:01 -0500
                Re: Java servlet on browsers: dying or kicking ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-01-05 01:32 +0000
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-06 10:27 +0000
                Re: Java servlet on browsers: dying or kicking ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-01-06 10:29 -0400
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-06 16:29 +0000
                Re: Java servlet on browsers: dying or kicking ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-01-06 13:46 -0400
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-06 18:44 +0000
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 21:10 -0500
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-07 09:04 +0000
                Re: Java servlet on browsers: dying or kicking ? Lew <lewbloch@gmail.com> - 2013-01-06 09:53 -0800
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-06 18:21 +0000
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 21:07 -0500
                Re: Java servlet on browsers: dying or kicking ? Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 21:18 -0500
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 21:28 -0500
                Re: Java servlet on browsers: dying or kicking ? Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 21:58 -0500
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 22:04 -0500
                Re: Java servlet on browsers: dying or kicking ? Twirlip of the Mists <twirlip@killfile.me.now.invalid> - 2013-01-06 22:10 -0500
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-07 08:34 +0000
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-07 08:25 +0000
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 10:34 -0500
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-06 16:46 +0000
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 21:05 -0500
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-06 17:10 +0000
                Re: Java servlet on browsers: dying or kicking ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-01-06 14:04 -0400
                Re: Java servlet on browsers: dying or kicking ? Arne Vajhøj <arne@vajhoej.dk> - 2013-01-06 21:03 -0500
                Re: Java servlet on browsers: dying or kicking ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-01-07 07:01 -0400
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-07 11:11 +0000
                Re: Java servlet on browsers: dying or kicking ? lipska the kat <lipskathekat@yahoo.co.uk> - 2013-01-07 14:25 +0000
                Re: Java servlet on browsers: dying or kicking ? "Richard Maher" <maher_rj@hotspamnotmail.com> - 2013-01-05 08:05 +0800
  Re: Java servlet on browsers: dying or kicking ? Lew <lewbloch@gmail.com> - 2012-12-24 11:06 -0800
    Re: Java servlet on browsers: dying or kicking ? Robert Klemme <shortcutter@googlemail.com> - 2012-12-24 23:33 +0100
      Re: Java servlet on browsers: dying or kicking ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-12-24 18:15 -0500
        Re: Java servlet on browsers: dying or kicking ? Robert Klemme <shortcutter@googlemail.com> - 2012-12-25 10:43 +0100
      Re: Java servlet on browsers: dying or kicking ? Lew <lewbloch@gmail.com> - 2012-12-25 13:21 -0800
  Re: Java servlet on browsers: dying or kicking ? Roedy Green <see_website@mindprod.com.invalid> - 2013-01-01 12:29 -0800

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