jsr342-experts@javaee-spec.java.net

[jsr342-experts] Re: Configuration

From: Werner Keil <werner.keil_at_gmail.com>
Date: Fri, 9 Sep 2011 11:37:57 +0200

On Thu, Sep 8, 2011 at 5:55 PM, Adam Bien <abien_at_adam-bien.com> wrote:

>
> On 08.09.2011, at 15:56, Werner Keil wrote:
>
> Jeff, that's a good point, one of the drawbacks of pure annotation-based
> approaches like JSR-330 and its likes.
>
> Although both were deployed in the same format (mostly XML and Properties)
> what was used in an earlier EE5 generation app I worked on in recent months,
> was pretty much having external resources override defaults from
> compile-time, which in our case could be annotation-based.
>
>
> Usually you are going to deploy the application on every change anyway. At
> least if you have a working CI environment in place. In this case it really
> doesn't matter whether you are going to edit the XML (usually without proper
> tooling), or change configuration on annotations.
>
>
Redeploy sure, but ideally not necessarily compile everything, e.g. if you
had only annotations. In cases where clients had the solution without
override, the "*DevOOps*" team ended up manually unpacking the WAR or EAR
just to change something in it, or even rebuild some artifacts.

After our work was done, most of it was covered by a working CI environment,
but bureaucratic rather than technical barriers usually still forces them to
copy stuff manually[?]


> Further there should be a possibility to override the annotations by e.g.
> XML or Java config.
>
>
>
> Another app with the same client followed a compile-time only strategy,
> which caused the problem of having to rebuild everything, at least the parts
> with changing resources for each target environment. For a large
> multi-tenant cloud that would be a nightmare<322.gif>
>
>
> On Thu, Sep 8, 2011 at 2:18 PM, Jeff Genender <jgenender_at_savoirtech.com>wrote:
>
>> The only problem with annotations for configuration is being able to see
>> it since its compiled. How would you know the values in the event that
>> needed changing? How would you override without a recompile? If we can have
>> a "switch" that enables override, that would be a possible option. I think
>> Java configuration would be neat, but we need the ability to override it
>> on-the-fly. I think ops guys would poop their pants if they didn't have that
>> ability ;-)
>>
>> Sorry for my long delay in response from 7/22… let me answer Bill's
>> statement from before….
>>
>> I (like Adam) don't think XML should be the overall reaching source. We
>> really should consider multiple ways to be able to do configurations, yes,
>> like a maven plugin. XML has been tried and try for many years, but it is
>> hated by many. I think allowing for multiple ways to configure gives
>> options to people for preferences on configuration and it brings EE up to
>> the 21st century ;-) I do like XML/JSON/Java configurations with the caveat
>> of having something that allows you to override the other (see my ops
>> comment above).
>>
>> As for JSON, there is an internet draft for this (
>> http://tools.ietf.org/html/draft-zyp-json-schema-03). Examples are at
>> http://json-schema.org/.
>>
>> Jeff
>>
>>
>> On Sep 8, 2011, at 5:39 AM, Adam Bien wrote:
>>
>> > Hi Reza + *,
>> >
>> > I only read the configuration-conversation without commenting it,
>> reason: I never configured any Java EE 5 / 6 application with XML. Sometimes
>> we had to configure the applications, but then we usually relied on a DB via
>> JDBC / JPA (usually the latter).
>> >
>> > In latest project I used the following approach to configure my Java EE
>> 6 apps:
>> http://www.adam-bien.com/roller/abien/entry/how_to_configure_java_ee The
>> defaults were overridden with data from DB.
>> >
>> > But: it should be possible to configure application with XML out of the
>> box. I would, hovewer, not use XML as "master", rather use Java object for
>> this purpose. The Java objects could be instantiated from XML, JSON (with
>> extended JAXB like it is the case in Jersey) and directly from DB (with or
>> without SQL), or directly by the application.
>> >
>> > I would also like to use annotations as a configuration source. We could
>> put the annotations on top of the java classes mentioned above.
>> >
>> > I like your XML-proposal but I do not like the fact that your are using
>> XML as the canonical model. As you mentioned previously: I would use
>> expressive Java classes as configuration source and XML / JSON / JPA as a
>> persistence mechanism.
>> >
>> > Any thoughts?
>> >
>> > thanks in advance!,
>> >
>> > adam
>> >
>> >
>> >
>> > On 23.07.2011, at 03:51, Reza Rahman wrote:
>> >
>> >> Bill,
>> >>
>> >> With all due respect, I think we are talking apples and oranges here.
>> >>
>> >> If you look at Spring for example, their newest and most popular
>> configuration styles is Java Config:
>> http://static.springsource.org/spring-javaconfig/docs/1.0.0.M4/reference/html/.
>> Similarly, the application configuration for the popular Wicket web
>> framework is also Java based and is one of the most well-liked features of
>> the technology. Jetty also allows for programmatic web application
>> configuration that is currently one of their unique features. None of theses
>> examples suffer from the same problems that EJB 1.0 did.
>> >>
>> >> At any rate, I do think I've said enough at this point. I think it's
>> time for others to voice their opinions if they believe this is something
>> that is valuable to the platform.
>> >>
>> >> Cheers,
>> >> Reza
>> >>
>> >>
>> >> On 7/22/2011 7:23 PM, Bill Shannon wrote:
>> >>> We used to have deployment descriptors written in Java.
>> >>> Remember EJB 1.0? Everyone hated them.
>> >>>
>> >>> Reza Rahman wrote on 07/22/11 04:01 PM:
>> >>>> Bill,
>> >>>>
>> >>>> I guess I'd like to discuss this more after we do see some more
>> tangible
>> >>>> interest in the EG at least :-). Something as pervasive as this
>> should
>> >>>> garner interest/input from a decent number of EG members :-).
>> >>>>
>> >>>> By definition, decoupling from XML as the "canonical" configuration
>> >>>> format to something more Java centric and more readily translatable
>> to
>> >>>> other formats allows for more choice/flexibility. I also disagree
>> with
>> >>>> Pete in that I do think a Java/OO-centric format is readily intuitive
>> >>>> and compelling to Java developers. As you mentioned, a revamp would
>> also
>> >>>> be a good opportunity to remove some of the old cruft and allow for
>> >>>> things like namespace based flexibility, better support for XML
>> >>>> attributes, overlaying vendor extension/plug-in configuration and so
>> on.
>> >>>>
>> >>>> For me personally, the option to write configuration in pure Java is
>> >>>> particularly tantalizing. It allows for possibilities like
>> >>>> programmatically changing configuration at deployment time (Servlet 3
>> >>>> does the very beginning of this in a very ad-hoc fashion). Just like
>> JPA
>> >>>> 2 criteria queries vs. JPQL, it is also more type-safe and arguably
>> more
>> >>>> readable/maintainable.
>> >>>>
>> >>>> Each alternative format similarly has it's own strengths -- JSON for
>> >>>> simplicity/brevity, property files for
>> familiarity/simplicity/brevity, etc.
>> >>>>
>> >>>> Cheers,
>> >>>> Reza
>> >>>>
>> >>>>
>> >>>> On 7/22/2011 5:31 PM, Bill Shannon wrote:
>> >>>>> Ok, good, you're not *all* on vacation! :-)
>> >>>>>
>> >>>>> Converting from our existing XML to JSON doesn't seem like a big
>> >>>>> improvement.
>> >>>>> Is there something like XML Schema for JSON?
>> >>>>>
>> >>>>> I assume the format of these files isn't a big issue for anyone
>> using
>> >>>>> an IDE.
>> >>>>> Are you trying to address the people who *don't* use an IDE? Would
>> it be
>> >>>>> enough to provide tools that convert JSON to XML? Perhaps a maven
>> >>>>> plugin?
>> >>>>>
>> >>>>>
>> >>>>> Jeff Genender wrote on 07/22/11 02:16 PM:
>> >>>>>> Now now… there is interest ;-) Its July and lots of holiday going
>> >>>>>> on… so be nice and understanding ;-)
>> >>>>>>
>> >>>>>> Im pretty high on the JSON stuff. This is gaining traction and
>> >>>>>> becoming a much more readable format. It would be nice to see a
>> >>>>>> paradigm shift and begin using some of the more friendlier data
>> formats.
>> >>>>>>
>> >>>>>> There is some interest, see? ;-)
>> >>>>>>
>> >>>>>> Jeff
>> >>>>>>
>> >>>>>> On Jul 22, 2011, at 3:09 PM, Bill Shannon wrote:
>> >>>>>>
>> >>>>>>> Reza Rahman wrote on 07/22/11 01:59 PM:
>> >>>>>>>> Bill,
>> >>>>>>>>
>> >>>>>>>> I guess it's a little disheartening that no one else on the alias
>> is
>> >>>>>>>> chiming in on this - not sure if this is just that boring or that
>> they
>> >>>>>>>> are judiciously biding their time :-).
>> >>>>>>>
>> >>>>>>> Ya, with this little interest here, it's not clear that it's worth
>> >>>>>>> making any of the proposed changes.
>> >>>>>>>
>> >>>>>>>> Anyways, would it help much that this approach might open the
>> >>>>>>>> doorway to
>> >>>>>>>> 100% XML free, Java based configuration down the line or that it
>> >>>>>>>> greases
>> >>>>>>>> the wheels for other possibilities like JSON or property file
>> based
>> >>>>>>>> DDs?
>> >>>>>>>
>> >>>>>>> I don't see why we need more ways of doing the same thing. You
>> need to
>> >>>>>>> convince me that any of these is so much better than what we
>> already
>> >>>>>>> have
>> >>>>>>> that it's worth doing.
>> >>>>>>>
>> >>>>>>>> It also helps make configuring CDI style DI easier for any
>> managed
>> >>>>>>>> bean...
>> >>>>>>>
>> >>>>>>> And that seems good.
>> >>>>>>>
>> >>>>>>>> To be honest though, I think just getting some kind of CDI XML in
>> Java
>> >>>>>>>> EE 7 would be a good accomplishment in the scheme of things. I've
>> >>>>>>>> never
>> >>>>>>>> been a proponent of making big changes in the standard without
>> some
>> >>>>>>>> implementation precedent. If we defer the general overhaul of
>> Java
>> >>>>>>>> EE DD
>> >>>>>>>> to Java EE 8, this does give us (and hopefully others) a little
>> more
>> >>>>>>>> room to do some "bleeding edge" implementation work on our own
>> >>>>>>>> terms. As
>> >>>>>>>> far as you can see, there is nothing in the standard that stops
>> us
>> >>>>>>>> from
>> >>>>>>>> doing that, right?
>> >>>>>>>
>> >>>>>>> Right. I think it's fine for CDI to blaze the trail here and we
>> can
>> >>>>>>> consider following their lead in EE 8.
>> >>>>>>>
>> >>>>>>> But only if I see more interest in this expert group! :-)
>> >>>>>>
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>> -----
>> >>>>> No virus found in this message.
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>> 07/22/11
>> >>>>>
>> >>>>>
>> >>>>
>> >>>
>> >>>
>> >>>
>> >>> -----
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>> >>>
>> >>>
>> >>
>> >
>> >
>>
>>
>
>
> --
>
> Werner Keil | UOMo Lead | Eclipse.org
>
> Twitter @wernerkeil | Skype: werner.keil | www.eclipse.org/uomo |
> #EclipseUOMo
>
> * JavaOne: October 2-6 2011, San Francisco, USA. Werner Keil, Agile Coach,
> UOMo Lead will co-present "JSR 321: Trusted Java API"
>
>
> Independent Consultant, Speaker, Java Champion
>
> Weblog: blog.adam-bien.com
> press: press.adam-bien.com
> eMail: abien_at_adam-bien.com
> twitter: twitter.com/AdamBien
> Mobile: 0049(0)170 280 3144
>
> Author of:
> "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking
> Best Practices"
>
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-- 
 Werner Keil | UOMo Lead | Eclipse.org
 Twitter @wernerkeil | Skype: werner.keil | www.eclipse.org/uomo |
#EclipseUOMo
* JavaOne: October 2-6 2011, San Francisco, USA. Werner Keil, Agile Coach,
UOMo Lead will co-present "JSR 321: Trusted Java API"



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