a bt off topic but wouldn't a wiki - confluence - be more efficient
for such discussion. When something is under discussion we put a kind
of poll/table with possibilities and when done we have more or less
some spec/doc.

issue with mails is we switch easily of topic and we need to summarize
regularly.

wdyt?


Romain Manni-Bucau
@rmannibucau
http://www.tomitribe.com
http://rmannibucau.wordpress.com
https://github.com/rmannibucau


2014-12-01 20:12 GMT+01:00 Anatole Tresch <[email protected]>:
> That is also the reason, why I suggested to postpone the assembly/providing
> discussion until we have at least a basic idea of
>
>    - PropertyProviders (building blocks)
>    - default combination mechanism that help defining new config/providers
>    for doing filtering, aggregation, overriding, security, views, ...
>    - Configuration (representation and SE access)
>    - Environment (basic environment model and access
>    - Basic Services (still SE): injection, configuration templates, dynamic
>    expressions
>    - implementing config changes (events)
>
> Then we are able to really talk about how to best support power users (the
> ones that setup the configuration meta-model) for
>
>    - implementing the configuration providers in a system
>    - dynamically loading property providers in the right context
>    - combining all that stuff with CDI (and Java EE)
>    - ...
>
> It is not that I want to prevent any discussions, I just want to add some
> minimal structure to it, so we are more effective ;)
>
> -Anatole
>
>
> 2014-12-01 19:48 GMT+01:00 Gerhard Petracek <[email protected]>:
>
>> @romain:
>> i just mentioned it (as one possibility), because oliver asked about
>> multiple config-sources which provide values for the same key.
>> independent of the final approach we will agree on (for that use-case), it
>> shouldn't affect the use-case we discuss right now.
>> (that's the reason for discussing it step by step and if a more complex
>> case really impacts a simple(r) case later on, we can re-visit the
>> corresponding api + tests at any time).
>>
>> regards,
>> gerhard
>>
>>
>>
>> 2014-12-01 19:34 GMT+01:00 Werner Keil <[email protected]>:
>>
>> > That's where some sort of "scope" is clearly necessary, see the different
>> > CDI scopes.
>> > It might make sense to inject a configuration via @Inject too btw. CDI
>> (and
>> > AFAIK DeltaSpike) rarely uses singletons or public factories along the
>> > lines of JSR 354.
>> > A single class and public accessor can be found in BeanValidation:
>> > Validation.
>> > That has a default factory but also offers other providers. If we needed
>> > something similar for Configuration then maybe something like
>> > getDefault...() could be more appropriate than simply calling it
>> > getInstance() ;-)
>> >
>> > On Mon, Dec 1, 2014 at 7:24 PM, Romain Manni-Bucau <
>> [email protected]>
>> > wrote:
>> >
>> > > if you have tamaya in server/lib and call it from webapps for
>> > > instance, each webapp can use different providers so you need
>> > > different instances. That is no more a singleton. If it is still one
>> > > cause we consider it as a factory/builder then the "instance" is
>> > > useless no?
>> > >
>> > >
>> > > Romain Manni-Bucau
>> > > @rmannibucau
>> > > http://www.tomitribe.com
>> > > http://rmannibucau.wordpress.com
>> > > https://github.com/rmannibucau
>> > >
>> > >
>> > > 2014-12-01 19:20 GMT+01:00 Werner Keil <[email protected]>:
>> > > > If you get one by app, is there any form of "context" you'd pass to
>> > such
>> > > > factory method?
>> > > >
>> > > > Currency.getInstance() returns exactly one singleton instance of a
>> > > Currency
>> > > > class (otherwise has no constructor either) for a given currency
>> code.
>> > > > While Money.of() in JSR 354 RI returns totally different instances
>> > > > depending on the combination of (nearly unlimited) different numbers
>> > and
>> > > > currency codes. 354 tries to broaden the definition of Currency, but
>> if
>> > > you
>> > > > get exactly one distinct instance per VM/app that's a singleton IMHO
>> > even
>> > > > if you may call the same application multiple times.
>> > > >
>> > > > On Mon, Dec 1, 2014 at 7:12 PM, Romain Manni-Bucau <
>> > > [email protected]>
>> > > > wrote:
>> > > >
>> > > >> Hmm,
>> > > >>
>> > > >> for me getInstance() = singleton  in term of instance where
>> > > >> Configuration will be all but a singleton IMO (you'll get at least
>> one
>> > > >> by app and surely a new instance each time you call it) no?
>> > > >>
>> > > >>
>> > > >> Romain Manni-Bucau
>> > > >> @rmannibucau
>> > > >> http://www.tomitribe.com
>> > > >> http://rmannibucau.wordpress.com
>> > > >> https://github.com/rmannibucau
>> > > >>
>> > > >>
>> > > >> 2014-12-01 18:56 GMT+01:00 Werner Keil <[email protected]>:
>> > > >> > Hi,
>> > > >> >
>> > > >> > Adding to the question of convenience factories, there is no such
>> > > thing
>> > > >> as
>> > > >> > "naming convention" by Stephen Colebourne or JSR 310. In fact, it
>> > > >> violates
>> > > >> > or bends almost every one of them in itself, so a suggestion like
>> > > >> > Configuration.current() would sound very similar to the
>> > > >> LocalDateTime.now()
>> > > >> > ones in 310.
>> > > >> > For several other cases of() or longer variations (like ofMilli()
>> > > >> ofNanos()
>> > > >> > etc.;-O) are used, while static factories from strings similar to
>> > what
>> > > >> JSR
>> > > >> > 354 adopted are called parse(String).
>> > > >> >
>> > > >> > Josh Bloch defined a clear distinction between what he then in
>> most
>> > > cases
>> > > >> > (except EnumSet, that's where he started using of() so Josh also
>> > > >> "invented"
>> > > >> > that while it violated some of his earlier naming conventions;-D)
>> > > called
>> > > >> > valueOf() and getInstance(), see
>> > > >> >
>> > > >>
>> > >
>> >
>> http://blog.codefront.net/2003/06/21/java-tip-2-static-factory-methods-vs-constructors/
>> > > >> > getInstance() returns a singleton, either the only instance for
>> this
>> > > type
>> > > >> > of object or the only instance for a distinct code or enum (see
>> > > >> > java.util.Currency)
>> > > >> >
>> > > >> > Very recent APIs and JSRs like MEEP 8 make a clear distinction,
>> and
>> > > >> classes
>> > > >> > like
>> > > >> >
>> > > >>
>> > >
>> >
>> https://docs.oracle.com/javame/8.0/api/meep/api/javax/microedition/event/EventManager.html
>> > > >> > clearly explain that, too. In other places ME 8 uses of() where
>> > > >> appropriate.
>> > > >> > So at least getInstance() is neither outdated nor wrong, it just
>> > > depends
>> > > >> on
>> > > >> > what you return.
>> > > >> >
>> > > >> > If Configuration returns just a default instance then
>> > > >> > Configuration.getInstance() seems appropriate.
>> > > >> >
>> > > >> >
>> > > >> >  Werner Keil | JCP Executive Committee Member, JSR 363 Co Spec
>> Lead
>> > |
>> > > >> > Eclipse UOMo Lead, Babel Language Champion | Apache Committer
>> > > >> >
>> > > >> > Twitter @wernerkeil | @UnitAPI | @JSR354 | @DeviceMap |
>> > #EclipseUOMo |
>> > > >> > #Java_Social
>> > > >> > | #DevOps
>> > > >> > Skype werner.keil | Google+ gplus.to/wernerkeil
>> > > >> >
>> > > >> > On Mon, Dec 1, 2014 at 6:31 PM, Oliver B. Fischer <
>> > > >> [email protected]>
>> > > >> > wrote:
>> > > >> >
>> > > >> >> Hi,
>> > > >> >>
>> > > >> >> for me the most simple use case is
>> > > >> >>
>> > > >> >>   Configuration conf = new Configuration();
>> > > >> >>   String value = conf.get("key")
>> > > >> >>
>> > > >> >> And this use case is already very complex under the hood.
>> > > >> >>
>> > > >> >> Before discussing other details we have to decide how
>> > > PropertyProviders
>> > > >> >> are activated.
>> > > >> >>
>> > > >> >> I would like to have the following possibilites:
>> > > >> >>
>> > > >> >> 1. Tamaya activates all PropertyProviders found in the classpath
>> > and
>> > > >> >> activated via SPI.
>> > > >> >> 2. Tamaya activates only a explicitly named list of Property
>> > > providers
>> > > >> >> 3. I have the ability to control the order in which the property
>> > > >> solution
>> > > >> >> will be performed
>> > > >> >>
>> > > >> >> Bye,
>> > > >> >>
>> > > >> >> Oliver
>> > > >> >>
>> > > >> >>
>> > > >> >> Am 01.12.14 17:54, schrieb Romain Manni-Bucau:
>> > > >> >>
>> > > >> >>> Configuration.current() sounds easier to understand first time
>> you
>> > > see
>> > > >> >>> it. I like Configuration.newInstance() if that's really what it
>> > does
>> > > >> >>> (ie no caching by classloader or anything else).
>> > > >> >>>
>> > > >> >>>
>> > > >> >>> Romain Manni-Bucau
>> > > >> >>> @rmannibucau
>> > > >> >>> http://www.tomitribe.com
>> > > >> >>> http://rmannibucau.wordpress.com
>> > > >> >>> https://github.com/rmannibucau
>> > > >> >>>
>> > > >> >>>
>> > > >> >>> 2014-12-01 17:42 GMT+01:00 Anatole Tresch <[email protected]>:
>> > > >> >>>
>> > > >> >>>> There is a naming concept from Stephen Colebourne when to use
>> of,
>> > > >> from,
>> > > >> >>>> with. I try to lookup the link later, see also jsr 310 and 354.
>> > > >> >>>> getInstance, valueOf are considered to be outdated for modern
>> api
>> > > >> design.
>> > > >> >>>>
>> > > >> >>>> Adding a helper, why? Another artifact a user must know, makes
>> > > sense,
>> > > >> >>>> where
>> > > >> >>>> you have a huge acces api IMO (see PropertyProviders where the
>> > > factory
>> > > >> >>>> methods are not part of the PropertyProvider interface. For
>> > > >> >>>> Configuration I
>> > > >> >>>> prefer having sn intuitive simple/single access...
>> > > >> >>>>
>> > > >> >>>> Nevertheless I would like to encourage you to make a concrete
>> > > proposal
>> > > >> >>>> how
>> > > >> >>>> would name things, so we can compare what your idea of fluent
>> is
>> > ;)
>> > > >> >>>>
>> > > >> >>>> -anatole
>> > > >> >>>> Gerhard Petracek <[email protected]> schrieb am Mo.,
>> 1.
>> > > Dez.
>> > > >> >>>> 2014
>> > > >> >>>> um 17:24:
>> > > >> >>>>
>> > > >> >>>>  hi anatole,
>> > > >> >>>>>
>> > > >> >>>>> again - yes and no.
>> > > >> >>>>> no - it wasn't similar before, because you haven't started
>> with
>> > > the
>> > > >> most
>> > > >> >>>>> trivial usage (supported by tamaya right now).
>> > > >> >>>>> however, now we are talking about a "different part" of the
>> api
>> > > >> which is
>> > > >> >>>>> very similar -> yes
>> > > >> >>>>>
>> > > >> >>>>> -> let's discuss
>> > > >> >>>>>    String myValue =
>> > Configuration.of().get("myKey").orElse(null);
>> > > >> >>>>>
>> > > >> >>>>> maybe we can get something better than ".of().get" or we
>> > provide a
>> > > >> >>>>> static
>> > > >> >>>>> helper for it.
>> > > >> >>>>> currently this first part doesn't read fluently. a lot of
>> users
>> > > might
>> > > >> >>>>> not
>> > > >> >>>>> need more than that (at least in the beginning) and therefore
>> it
>> > > >> should
>> > > >> >>>>> be
>> > > >> >>>>> nice.
>> > > >> >>>>>
>> > > >> >>>>> regards,
>> > > >> >>>>> gerhard
>> > > >> >>>>>
>> > > >> >>>>>
>> > > >> >>>>>
>> > > >> >>>>> 2014-12-01 16:07 GMT+01:00 Tresch, Anatole
>> > > >> >>>>> <anatole.tresch@credit-suisse.
>> > > >> >>>>> com
>> > > >> >>>>>
>> > > >> >>>>>> :
>> > > >> >>>>>> Hi Gerhard
>> > > >> >>>>>>
>> > > >> >>>>>> as I said granularity is not matching in your example.
>> > Comparing
>> > > >> >>>>>> concepts
>> > > >> >>>>>> on the same granularity level it would be:
>> > > >> >>>>>>
>> > > >> >>>>>>      String myValue =
>> ConfigResolver.getPropertyValue("myKey");
>> > >  //
>> > > >> >>>>>> Deltaspike
>> > > >> >>>>>>
>> > > >> >>>>>> compared to:
>> > > >> >>>>>>
>> > > >> >>>>>>      String myValue =
>> > > Configuration.of().get("myKey").orElse(null);
>> > > >> >>>>>> //
>> > > >> >>>>>> Tamaya
>> > > >> >>>>>>
>> > > >> >>>>>> So that looks more or less similar (I did not count the
>> > > characters)
>> > > >> ;)
>> > > >> >>>>>>
>> > > >> >>>>>> It will be interesting to see how it feels, when defining the
>> > > model
>> > > >> >>>>>>
>> > > >> >>>>> behind
>> > > >> >>>>>
>> > > >> >>>>>> this facades. Tamaya can support dynamic property providers
>> > (aka
>> > > >> >>>>>> PropertySource) managed by CDI for app config as well. But on
>> > > top of
>> > > >> >>>>>> them
>> > > >> >>>>>> also will probably be capable to configure CDI and other
>> > aspects.
>> > > >> >>>>>> Already
>> > > >> >>>>>> in place is a Properties implementation that can be applied
>> to
>> > > >> >>>>>> System.setProperties(Properties), which adds dynamic
>> > > >> >>>>>>
>> > > >> >>>>> (configurable)system
>> > > >> >>>>>
>> > > >> >>>>>> properties as a minimal shared level of API already available
>> > as
>> > > of
>> > > >> now
>> > > >> >>>>>>
>> > > >> >>>>> on
>> > > >> >>>>>
>> > > >> >>>>>> SE level.
>> > > >> >>>>>>
>> > > >> >>>>>> -Anatole
>> > > >> >>>>>>
>> > > >> >>>>>>
>> > > >> >>>>>> -----Original Message-----
>> > > >> >>>>>> From: Gerhard Petracek [mailto:[email protected]]
>> > > >> >>>>>> Sent: Montag, 1. Dezember 2014 14:30
>> > > >> >>>>>> To: [email protected]
>> > > >> >>>>>> Subject: Re: Use Case 1: Read simple properties and get
>> values.
>> > > >> >>>>>>
>> > > >> >>>>>> hi anatole,
>> > > >> >>>>>>
>> > > >> >>>>>> yes and no - the part i talked about mainly is:
>> > > >> >>>>>> String myValue = ConfigResolver.getPropertyValue("myKey");
>> > > >> >>>>>>
>> > > >> >>>>>> compared to:
>> > > >> >>>>>> Configuration config = PropertyProviders.fromPaths(/*...*/);
>> > > >> >>>>>> String myValue = config.get("myKey", String.class);
>> > > >> >>>>>>
>> > > >> >>>>>> regards,
>> > > >> >>>>>> gerhard
>> > > >> >>>>>>
>> > > >> >>>>>>
>> > > >> >>>>>>
>> > > >> >>>>>> 2014-12-01 14:22 GMT+01:00 Anatole Tresch <
>> [email protected]
>> > >:
>> > > >> >>>>>>
>> > > >> >>>>>>  Hi Gerhard
>> > > >> >>>>>>> What you describe is use case that will follow later. You
>> > asked
>> > > me
>> > > >> to
>> > > >> >>>>>>>
>> > > >> >>>>>> start
>> > > >> >>>>>>
>> > > >> >>>>>>> with a simple one, so this is the most simple one. Next use
>> > > cases
>> > > >> will
>> > > >> >>>>>>>
>> > > >> >>>>>> add
>> > > >> >>>>>>
>> > > >> >>>>>>> aadditional sources, then we will combine things (aka
>> complex
>> > > >> >>>>>>>
>> > > >> >>>>>> overridings).
>> > > >> >>>>>>
>> > > >> >>>>>>> After that we will emphasize on the environment model,
>> because
>> > > this
>> > > >> >>>>>>>
>> > > >> >>>>>> defines
>> > > >> >>>>>>
>> > > >> >>>>>>> the context, which determines which config is appropriate.
>> The
>> > > >> user in
>> > > >> >>>>>>>
>> > > >> >>>>>> most
>> > > >> >>>>>>
>> > > >> >>>>>>> cases will call Configuration.of() to access.the current
>> > > >> >>>>>>> configuration.
>> > > >> >>>>>>> This method then is backed by a config provider. This
>> provider
>> > > >> decides
>> > > >> >>>>>>>
>> > > >> >>>>>> how
>> > > >> >>>>>>
>> > > >> >>>>>>> the current environment is determining the config to be
>> > returned
>> > > >> (aka
>> > > >> >>>>>>> defines implements the config metamodel).
>> > > >> >>>>>>> This metamodel can be defined rather differently depending
>> > your
>> > > >> target
>> > > >> >>>>>>> runtime and require config solutions. And for this we
>> require
>> > > the
>> > > >> >>>>>>>
>> > > >> >>>>>> basics
>> > > >> >>>>>
>> > > >> >>>>>> (where I started).
>> > > >> >>>>>>>
>> > > >> >>>>>>> What is in Deltaspike as of now is only a subset of what I
>> see
>> > > >> >>>>>>>
>> > > >> >>>>>> necessary
>> > > >> >>>>>
>> > > >> >>>>>> to
>> > > >> >>>>>>
>> > > >> >>>>>>> build a compelling config system. We will be able to cover
>> > that
>> > > >> >>>>>>> functionality easily and it will be easy to use.
>> > > >> >>>>>>>
>> > > >> >>>>>>> So please have some patience and let me post the use cases
>> and
>> > > >> >>>>>>>
>> > > >> >>>>>> solutions
>> > > >> >>>>>
>> > > >> >>>>>> one by one and focus on these. I try to post them if possible
>> > on
>> > > a
>> > > >> >>>>>>>
>> > > >> >>>>>> daily
>> > > >> >>>>>
>> > > >> >>>>>> basis. Hopefully we will have then a common terminology and
>> > > >> >>>>>>>
>> > > >> >>>>>> architectural
>> > > >> >>>>>
>> > > >> >>>>>> view on the whole topic that helps us discuss things
>> > efficiently
>> > > ;)
>> > > >> >>>>>>>
>> > > >> >>>>>>> Cheers
>> > > >> >>>>>>> Anatole
>> > > >> >>>>>>>
>> > > >> >>>>>>> Gerhard Petracek <[email protected]> schrieb am
>> Mo.,
>> > > 1.
>> > > >> Dez.
>> > > >> >>>>>>>
>> > > >> >>>>>> 2014
>> > > >> >>>>>>
>> > > >> >>>>>>> um 13:58:
>> > > >> >>>>>>>
>> > > >> >>>>>>>  hi @ all,
>> > > >> >>>>>>>>
>> > > >> >>>>>>>> @anatole: thx for starting this thread.
>> > > >> >>>>>>>>
>> > > >> >>>>>>>> let's start/continue with the first part - the equivalent
>> in
>> > > >> >>>>>>>>
>> > > >> >>>>>>> deltaspike
>> > > >> >>>>>
>> > > >> >>>>>> is:
>> > > >> >>>>>>>
>> > > >> >>>>>>>> String myValue = ConfigResolver.getPropertyValue("myKey");
>> > > >> >>>>>>>>
>> > > >> >>>>>>>> as a precondition for this call, you need 1-n registered
>> > > >> >>>>>>>>
>> > > >> >>>>>>> config-source(s)
>> > > >> >>>>>>
>> > > >> >>>>>>> (= std. spi config -> in this case in:
>> > > >> >>>>>>>> META-INF/services/org.apache.deltaspike.core.spi.config.
>> > > >> >>>>>>>>
>> > > >> >>>>>>> ConfigSource).
>> > > >> >>>>>
>> > > >> >>>>>> this approach is nice for >applications<, because everything
>> is
>> > > done
>> > > >> >>>>>>>> automatically based on the "visible" configs.
>> > > >> >>>>>>>> furthermore, it's very flexible, because a config-source
>> > > >> encapsulates
>> > > >> >>>>>>>>
>> > > >> >>>>>>> the
>> > > >> >>>>>>
>> > > >> >>>>>>> logic for different config-locations (files, jndi, db,...).
>> > > >> >>>>>>>>
>> > > >> >>>>>>>> mark wrote that part -> he might add some details which are
>> > > >> important
>> > > >> >>>>>>>>
>> > > >> >>>>>>> to
>> > > >> >>>>>>
>> > > >> >>>>>>> him (for the >current< use-case):
>> > > >> >>>>>>>>
>> > > >> >>>>>>>> regards,
>> > > >> >>>>>>>> gerhard
>> > > >> >>>>>>>>
>> > > >> >>>>>>>>
>> > > >> >>>>>>>>
>> > > >> >>>>>>>> 2014-12-01 11:30 GMT+01:00 Romain Manni-Bucau <
>> > > >> [email protected]
>> > > >> >>>>>>>>
>> > > >> >>>>>>> :
>> > > >> >>>>>>
>> > > >> >>>>>>> Looks like a good entry point, I like the "prefixing" to
>> > switch
>> > > of
>> > > >> >>>>>>>>> "reader". However I don't like to be forced to use an
>> > > Optional.
>> > > >> In
>> > > >> >>>>>>>>> several cases I prefer to stick to properties API ie get
>> > > >> something
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>> or
>> > > >> >>>>>
>> > > >> >>>>>> a default, default being null if not set when queried.
>> Optional
>> > > is
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>> not
>> > > >> >>>>>>
>> > > >> >>>>>>> bad but makes code very verbose for pretty much nothing is
>> > > several
>> > > >> >>>>>>>>> cases (of config).
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>> wdyt?
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>> Romain Manni-Bucau
>> > > >> >>>>>>>>> @rmannibucau
>> > > >> >>>>>>>>> http://www.tomitribe.com
>> > > >> >>>>>>>>> http://rmannibucau.wordpress.com
>> > > >> >>>>>>>>> https://github.com/rmannibucau
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>> 2014-12-01 11:15 GMT+01:00 Anatole Tresch <
>> > [email protected]
>> > > >:
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> Hi all
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> I have put together a first couple of simple use cases.
>> It
>> > is
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> targeting
>> > > >> >>>>>>>
>> > > >> >>>>>>>> SE
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> level only (as many use cases will do, especially the
>> basic
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> ones).
>> > > >> >>>>>
>> > > >> >>>>>> *Basic use case 1:*
>> > > >> >>>>>>>>>> We want to write some properties file and read it from a
>> > > file or
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> the
>> > > >> >>>>>>
>> > > >> >>>>>>> classpath into a Configuration instance. This is done by
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> Configuration config = PropertyProviders.fromPaths(
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>>  "classpath:ucs/UC1ReadProperties/UC1ReadPropertiesTest.
>> > > >> >>>>>>> properties")
>> > > >> >>>>>>>
>> > > >> >>>>>>>>     .toConfiguration();
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> The PropertyProvider which is created here by
>> > > >> >>>>>>>>>> PropertyProviders.fromPaths hereby
>> > > >> >>>>>>>>>> is a simplified version that can be easily aggregated
>> (for
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> composites)
>> > > >> >>>>>>>
>> > > >> >>>>>>>> and
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> only provides String values (no type support yet).
>> > > Nevertheless
>> > > >> >>>>>>>>>> mapping to Configuration
>> > > >> >>>>>>>>>> is trivial.
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> Given that we then can access different values. Since we
>> > > return
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> Optional
>> > > >> >>>>>>>>
>> > > >> >>>>>>>>> as
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> a result type the values returned are never null. For
>> > showing
>> > > >> the
>> > > >> >>>>>>>>>> capabilities I added multiple examples of types:
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> String name = config.get("name").orElse("Anatole");
>> > > >> >>>>>>>>>> BigDecimal bigNum = config.get("num.BD",
>> BigDecimal.class)
>> > > >> >>>>>>>>>>                            .orElseThrow(() -> new
>> > > >> >>>>>>>>>> IllegalStateException("Sorry"));
>> > > >> >>>>>>>>>> double anotherNum = config.getDouble("num.Double")
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> .getAsDouble();
>> > > >> >>>>>
>> > > >> >>>>>> long longNum = config.getLong("num.Long").orElse(288900L);
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> Finally plugins or modules often only want a view on
>> their
>> > > >> subset
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> of
>> > > >> >>>>>>
>> > > >> >>>>>>> entries. This can be achieved easily by using
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> Configuration areaConfig2 =
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> config.with(ConfigFunctions.selectArea("num"));
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> This will return a Configuration subset, which will only
>> > > contain
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> the
>> > > >> >>>>>>
>> > > >> >>>>>>> child
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> values of the num area, which are BD, double, ...
>> > > >> ConfigFunctions
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> BTW
>> > > >> >>>>>>
>> > > >> >>>>>>> is
>> > > >> >>>>>>>>
>> > > >> >>>>>>>>> a
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> dingleton accessot, which serves
>> > > >> >>>>>>>>>> ConfigOperator functional extensions (there is also a
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> ConfigQuery),
>> > > >> >>>>>
>> > > >> >>>>>> so
>> > > >> >>>>>>>
>> > > >> >>>>>>>> this
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> is a common pattern for adding whatever extension needed
>> to
>> > > >> >>>>>>>>>> Configuration instances
>> > > >> >>>>>>>>>> without having them to directly implement/provide on
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> Configuration
>> > > >> >>>>>
>> > > >> >>>>>> itself.
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> All the features are reflected in the test class (in the
>> > core
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> module):
>> > > >> >>>>>>>
>> > > >> >>>>>>>>
>> org.apache.tamaya.uc.UC1ReadProperties.UC1ReadPropertiesTest
>> > > (we
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> should
>> > > >> >>>>>>>>
>> > > >> >>>>>>>>> lower case the package name ;) ).
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> This test also contains additional features/use cases...
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> *Extended use case 1.1: multiple formats*
>> > > >> >>>>>>>>>> It is possible to read multiple file formats, by default
>> > the
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> following
>> > > >> >>>>>>>
>> > > >> >>>>>>>> formats are supported
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>>     - .properties (as defined by java.util.Properties)
>> > > >> >>>>>>>>>>     - .xml properties (as defined by
>> java.util.Properties)
>> > > >> >>>>>>>>>>     - .ini format
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> Configuration config = PropertyProviders.fromPaths(
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>>  "classpath:ucs/UC1ReadProperties/UC1ReadPropertiesTest.
>> > > >> >>>>>>> properties",
>> > > >> >>>>>>>
>> > > >> >>>>>>>>
>> > >  "classpath:ucs/UC1ReadProperties/UC1ReadPropertiesTest.xml",
>> > > >> >>>>>>>>>>     "file:c:/temp/myProps.properties")
>> > > >> >>>>>>>>>>     .toConfiguration();
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> In the back format resolution is handled by an SPI, which
>> > is
>> > > >> >>>>>>>>>> extendable/pluggable.
>> > > >> >>>>>>>>>> The basic component here ist the ConfigurationFormats
>> > > singleton
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> and
>> > > >> >>>>>
>> > > >> >>>>>> the ConfigurationFormat
>> > > >> >>>>>>>>>> interfaCE.
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> *Extended use case 1.2: multiple sources*
>> > > >> >>>>>>>>>> It is possible to read multiple files, by adding
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>>     - additional paths (see above)
>> > > >> >>>>>>>>>>     - ant styled expressions
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> Configuration config = PropertyProviders.fromPaths(
>> > > >> >>>>>>>>>>
>> > >  "classpath:ucs/UC1ReadProperties/UC1ReadPropertiesTest.*",
>> > > >> >>>>>>>>>>     "classpath*:ucs/UC1ReadProperties/**/*.properties")
>> > > >> >>>>>>>>>>     .toConfiguration();
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> In the back resource resolution is handled by an SPI,
>> which
>> > > is
>> > > >> >>>>>>>>>> extendable/pluggable as well.
>> > file,file*,classpath,classpath*
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> are
>> > > >> >>>>>
>> > > >> >>>>>> the
>> > > >> >>>>>>
>> > > >> >>>>>>> locator ids which are implemented based on  a subset of the
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> Spring
>> > > >> >>>>>
>> > > >> >>>>>> resource
>> > > >> >>>>>>>>>
>> > > >> >>>>>>>>>> loader is working. Additional resource location mechanism
>> > > could
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> be
>> > > >> >>>>>
>> > > >> >>>>>> easily added by implementing the
>> > > >> >>>>>>>>>> org.apache.tamaya.core.internal.resources.PathResolver
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> interface.
>> > > >> >>>>>
>> > > >> >>>>>> If
>> > > >> >>>>>>
>> > > >> >>>>>>> one
>> > > >> >>>>>>>>
>> > > >> >>>>>>>>> implements and registers (using the Bootstrap component,
>> by
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> default
>> > > >> >>>>>
>> > > >> >>>>>> using
>> > > >> >>>>>>>>
>> > > >> >>>>>>>>> ServiceLoader), e.g. a resolver called "foo", the
>> expression
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> would
>> > > >> >>>>>
>> > > >> >>>>>> look
>> > > >> >>>>>>>
>> > > >> >>>>>>>> like:
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> Configuration config = PropertyProviders.fromPaths(
>> > > >> >>>>>>>>>>     "foo:myResourceExpression");
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> Next variants would be reading properties from other
>> > > resources.
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> We
>> > > >> >>>>>
>> > > >> >>>>>> could
>> > > >> >>>>>>>>
>> > > >> >>>>>>>>> e.g. create a programmatic random resource and also use a
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>> database,
>> > > >> >>>>>
>> > > >> >>>>>> or
>> > > >> >>>>>>>
>> > > >> >>>>>>>> remote resource.
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>> Cheers,
>> > > >> >>>>>>>>>> Anatole
>> > > >> >>>>>>>>>>
>> > > >> >>>>>>>>>>
>> > > >> >> --
>> > > >> >> N Oliver B. Fischer
>> > > >> >> A Schönhauser Allee 64, 10437 Berlin, Deutschland/Germany
>> > > >> >> P +49 30 44793251
>> > > >> >> M +49 178 7903538
>> > > >> >> E [email protected]
>> > > >> >> S oliver.b.fischer
>> > > >> >> J [email protected]
>> > > >> >> X http://xing.to/obf
>> > > >> >>
>> > > >> >>
>> > > >>
>> > >
>> >
>>
>
>
>
> --
> *Anatole Tresch*
> Java Engineer & Architect, JSR Spec Lead
> Glärnischweg 10
> CH - 8620 Wetzikon
>
> *Switzerland, Europe Zurich, GMT+1*
> *Twitter:  @atsticks*
> *Blogs: **http://javaremarkables.blogspot.ch/
> <http://javaremarkables.blogspot.ch/>*
>
> *Google: atsticksMobile  +41-76 344 62 79*

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