Use Advanced Search to search the entire archive.
Re: AbstractQuantity's class
- From: Otávio Gonçalves de Santana <
>
- To:
- Subject: Re: AbstractQuantity's class
- Date: Wed, 17 Sep 2014 04:23:07 -0300
Another proposal is, remove the factory methods in AbstractQuantity, remove
the public in the class and make it visibla just to the package, and create
the QuantityFactory:
I saw some advantagens:
- Hide the implementations
- Just show the API
- the client don't need know the implementation
- Single responsability to factory - now one class will do that
- the AbstractQuantity follows the SOLID principle
On Tue, Sep 16, 2014 at 3:55 AM, Werner Keil
<
>
wrote:
>
That's along the lines of similar ones in JDK or JavaMoney;-)
>
Would you avoid the of() method in concrete classes to solve Otavio's
>
Problem/question?
>
>
As Anatole is at Hackergarten, we can probably offer him to join if he
>
wants.
>
>
Cheers,
>
W
>
Am 16.09.2014 08:07 schrieb "Jean-Marie Dautelle"
>
<
>:
>
>
Hello,
>
> Quantities would not extends any class, its purpose is to provide static
>
> factory method. Starting with Java 8, interface may have static factory
>
> (but Java 8 it is not your target).
>
> I would stay away from static factory method, except to get the "quantity
>
> factory" (cf. unit of measurement 6.x api):
>
> MyQuantityFactory.getInstance().newQuantity("10 m");
>
> Cheers,
>
> JM
>
>
>
>
>
> On Tue, Sep 16, 2014 at 12:37 AM, Werner Keil
>
> <
>
>
> wrote:
>
>
>
>> Sorry but it is not the answer to the question you askd, there is no
>
>> practice (see JSR 354) like MonetaryAmounts.of() or Collections.of().
>
>>
>
>> Those are merely facade methods, a Quantities extends AbstractQuantity
>
>> makes no sense, it is just wrong.
>
>> Seems we probably need Hackergarten or the community to ask them for the
>
>> right name. It certainly is not Quantities based on all other APIs.
>
>>
>
>> Beside, if we start putting such facades like Quantities into the RI,
>
>> where does that leave the SPI elements or how wold it use them?
>
>>
>
>>
>
>>
>
>> On Tue, Sep 16, 2014 at 12:28 AM, Werner Keil
>
>> <
>
>
>> wrote:
>
>>
>
>>> What exactly should "Quantities" be, a facade like "MonetaryAmounts",
>
>>> etc. from JavaMoney??
>
>>>
>
>>> If it was to replace BaseQuantity, that is not a name for a concrete
>
>>> class I'm afraid. The TemporalAmount used in JSR 310 is actually a
>
>>> TemporalAmounts (since it represents more than a single amount) but if we
>
>>> had
>
>>> Quantities extends AbstractQuantity or
>
>>> Quantities implements Quantity??
>
>>>
>
>>>
>
>>> java.util.Collections does not implement java.util.Collection either,
>
>>> it is merely a facade, no need for an of() there[?]
>
>>> So what you suggested would be a facade along the lines of what Anatole
>
>>> mentioned, but it cannot replace AbstractQuantity.
>
>>>
>
>>> Class.of() returns an instance of that class, so a Quantities facade
>
>>> could offer a method like
>
>>>
>
>>> Quantities.getQuantityFactory(), but it can't extend or implement
>
>>> Quantity, nor return a Quantity as such via of().
>
>>>
>
>>> Regards,
>
>>> Werner
>
>>>
>
>>> On Mon, Sep 15, 2014 at 11:40 PM, Jean-Marie Dautelle <
>
>>>
>
>
>>> wrote:
>
>>>
>
>>>> Hi All,
>
>>>> Indeed, JScience use Amount but with a different semantics (using that
>
>>>> same name would create for me a headache due to name clashing).
>
>>>> It should be noted that Amount has to be a class (not an interface) in
>
>>>> order to provide static factory method (Java 7).
>
>>>> Usually (at least in JScience), you will have something like Amount
>
>>>> (interface) and Amounts with terminating s for the class holding static
>
>>>> factory method to produce Amount instances.
>
>>>> But since you intend to return Quantity types, I would suggest using
>
>>>> Quantities.of(100d, SI.METRE) - That would be consistent with standard
>
>>>> practices.
>
>>>> Best regards,
>
>>>> Jean-Marie.
>
>>>>
>
>>>>
>
>>>> On Mon, Sep 15, 2014 at 9:51 PM, Werner Keil
>
>>>> <
>
>
>>>> wrote:
>
>>>>
>
>>>>> Dear Experts,
>
>>>>>
>
>>>>> If you don't see a conflict between a more general "Amount" class
>
>>>>> here and other types in different value-oriented APIs like JSR 354, we
>
>>>>> may
>
>>>>> take the inspiration by the likes of JScience or ICU4J, both using
>
>>>>> *Amount
>
>>>>> for such types.
>
>>>>>
>
>>>>> ICU4J combines it with things like "Currency" in
>
>>>>> http://icu-project.org/apiref/icu4j/com/ibm/icu/util/CurrencyAmount.html
>
>>>>> the other concrete class is even called "TimeUnitAmount", but I would
>
>>>>> not really see any of those as proper additions either.
>
>>>>>
>
>>>>> How do you intend to use the "faster" quantity sub-types, currently
>
>>>>> all returned by factory methods in AbstractQuantity?
>
>>>>> The "Amount" type like e.g. that in ICU4J (there it is named Measure,
>
>>>>> but unlike JSR 363 it does not separate between API and
>
>>>>> implementation, so
>
>>>>> everything are classes) holds a Number, so in theory using different
>
>>>>> concrete number sub-classes would work for
>
>>>>> Amount.of(100d, SI.METRE) as opposed to
>
>>>>> Amount.of(BigDecimal.TEN, SI.METRE) could handle that all.
>
>>>>>
>
>>>>> What about alternate classes with a lower footprint, especially in
>
>>>>> SE? Actually they might matter more, but if using objects like Double,
>
>>>>> Integer or Long worked equally well under ME, we could and should keep
>
>>>>> that
>
>>>>> in sync, with the exception of BigDecimal/BigInteger[?]
>
>>>>>
>
>>>>> Martin, others WDYT?
>
>>>>>
>
>>>>> Regards,
>
>>>>> Werner
>
>>>>>
>
>>>>> On Mon, Sep 15, 2014 at 9:07 PM, Otávio Gonçalves de Santana <
>
>>>>>
>
>
>>>>> wrote:
>
>>>>>
>
>>>>>> Amount.of() sounds good.
>
>>>>>> On Sep 15, 2014 4:04 PM, "Legrand, Karen"
>
>>>>>> <
>
>
>>>>>> wrote:
>
>>>>>>
>
>>>>>>> -1 for QuantityAmount. It looks very odd to have two nouns that
>
>>>>>>> are essentially synonyms together like that. I think it would be much
>
>>>>>>> better to use either ‘Quantity’ or ‘Amount’ by itself.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> *From:* Leonardo Lima
>
>>>>>>> [mailto:
]
>
>>>>>>> *Sent:* Monday, September 15, 2014 10:44 AM
>
>>>>>>> *To:*
>
>>>>>>>
>
>>>>>>> *Subject:* Re: AbstractQuantity's class
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> QuantityAmount sounds redundant, doesn't it?
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> On Sun, Sep 14, 2014 at 9:03 PM, Otávio Gonçalves de Santana <
>
>>>>>>>
>
>
>>>>>>> wrote:
>
>>>>>>>
>
>>>>>>> Actually I would like to work this and in Lambda expressions.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> Could be QuantityAmount then?
>
>>>>>>>
>
>>>>>>> anyone?
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> On Sun, Sep 14, 2014 at 6:06 PM, Werner Keil
>
>>>>>>> <
>
>
>>>>>>> wrote:
>
>>>>>>>
>
>>>>>>> Since we drop the .org domain soon, I would not call that UOMo (the
>
>>>>>>> Eclipse project certainly will keep the name, after all it also
>
>>>>>>> support
>
>>>>>>> UCUM which has another .org domain, too)
>
>>>>>>>
>
>>>>>>> Why would Quantities get an of() method? What would be imaginable
>
>>>>>>> is some sort of factory/facade in RI or SE, but except a
>
>>>>>>> getInstance(Length.class) similar to the current QuantityFactory
>
>>>>>>> class
>
>>>>>>> (it's a singleton returning exactly one instance here, see MEEP or
>
>>>>>>> CLDC8,
>
>>>>>>> they also use both of() and getInstance() for each purpose, just
>
>>>>>>> like Josh
>
>>>>>>> Bloch explained) there is nothing to be of() in this case.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> QuantityAmount sounds like a good alternative of these, let's see
>
>>>>>>> at JavaOne, probably in Hackergarten what's best.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> On Sun, Sep 14, 2014 at 9:01 PM, Otávio Gonçalves de Santana <
>
>>>>>>>
>
>
>>>>>>> wrote:
>
>>>>>>>
>
>>>>>>> I am not referring if the classe be or not be abstract or design,
>
>>>>>>> but just the name, I am talking about the nomenclature.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> Could be a good name:
>
>>>>>>>
>
>>>>>>> - UOMO.of(...)
>
>>>>>>>
>
>>>>>>> another one is:
>
>>>>>>>
>
>>>>>>> - Quantities.of(...)
>
>>>>>>>
>
>>>>>>> or the classic:
>
>>>>>>>
>
>>>>>>> - QuantityAmount.of(...)
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> On Sun, Sep 14, 2014 at 2:51 PM, Werner Keil
>
>>>>>>> <
>
>
>>>>>>> wrote:
>
>>>>>>>
>
>>>>>>> Sorry, no more Measurable, please
>
>>>>>>>
>
>>>>>>> We've been there once.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> You bet Spring was probably created a while ago and may not follow
>
>>>>>>> all patterns we may see now
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> Something else e.g. QuantityAmount<Q extends Quantity> extends
>
>>>>>>> AbstractQuantity<Q> is worth considering, like in UOMo.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> And the subsequent of() methods may be on such a concrete class.
>
>>>>>>>
>
>>>>>>> If you look at let's say the Collections API, it shows a similar
>
>>>>>>> pattern of
>
>>>>>>>
>
>>>>>>> Interface > AbstractBaseClass > ConcreteClass.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> This "author" may not have done everything consistently there, see
>
>>>>>>> EnumSet, but other than that it is still a better piece of API than
>
>>>>>>> let's
>
>>>>>>> say 310 with hundreds of methods on final classes that are largely
>
>>>>>>> incompatible and a TemporalAmount which actually should be called
>
>>>>>>> TemporalAmounts, TemporalAmountCollection or whatever
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> On Sun, Sep 14, 2014 at 8:32 AM, Werner Keil
>
>>>>>>> <
>
>
>>>>>>> wrote:
>
>>>>>>>
>
>>>>>>> Sorry but we had that confusion with JSR 275, so ONE Measurement is
>
>>>>>>> enough, we must not have Measure implements Measurement, that would
>
>>>>>>> just be
>
>>>>>>> a mess.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> JScience called that "Amount", but you see a lot of very popular
>
>>>>>>> projects (SpringFramework) doing exactly the same. There are
>
>>>>>>> Abstract*.valueOf() or similar constructions.
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> Regards,
>
>>>>>>>
>
>>>>>>> Werner
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> Werner Keil | JCP Executive Committee Member, JSR 363 Co Spec
>
>>>>>>> Lead | Eclipse UOMo Lead, Babel Language Champion | Apache
>
>>>>>>> Committer | Java Godfather
>
>>>>>>>
>
>>>>>>> Twitter @wernerkeil | @UnitAPI | @JSR354 | #EclipseUOMo |
>
>>>>>>> #Java_Social
>
>>>>>>> | #DevOps
>
>>>>>>>
>
>>>>>>> Skype werner.keil | Google+ gplus.to/wernerkeil
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> * JavaZone 2014: 9-11 Sep 2014, Oslo, Norway. Werner Keil, JCP EC
>
>>>>>>> Member, JSR 363 Spec Lead will present "JSR 363 - The Answer to
>
>>>>>>> Life Science and the Internet of Everything"
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> * JavaOne 2014: Sep 30, San Francisco, USA, Werner Keil, JCP EC
>
>>>>>>> Member, JSR 354 EG Member will host "Java and Digital Currencies,
>
>>>>>>> Friend or
>
>>>>>>> FOE"
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> * JMaghreb 3.0: 4-6 Nov 2014, Casablanca, Morocco. Werner Keil, JCP
>
>>>>>>> EC Member, JSR 363 Spec Lead, DevOps Guy will present "Triple-E'
>
>>>>>>> class DevOps", "JSR 363"
>
>>>>>>>
>
>>>>>>> * ApacheCon Europe: 17 Nov 2014, Budapest, Hungary. Werner Keil,
>
>>>>>>> JCP EC Member, Apache DeviceMap Committer will present "Apache
>
>>>>>>> DeviceMap"
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> * Mobile Developer Conference kompakt: 18 Nov 2014, Hamburg,
>
>>>>>>> Germany. Werner Keil, JCP EC Member, Apache DeviceMap Committer will
>
>>>>>>> present "Apache DeviceMap" (GER)
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> On Sun, Sep 14, 2014 at 12:29 PM, Otávio Gonçalves de Santana <
>
>>>>>>>
>
>
>>>>>>> wrote:
>
>>>>>>>
>
>>>>>>> Hi Guys.
>
>>>>>>>
>
>>>>>>> How is going?
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> I believe we have a possible problem with nomeclature in
>
>>>>>>> AbstractQuantity's class, looking this example:
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> Quantity<Length> metre = AbstractQuantity.of(10, SI.METRE);
>
>>>>>>>
>
>>>>>>> Quantity<Length> foot = metre.to(US.FOOT);
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> IMHO, Abstract* is not a good name to a factory, maybe just
>
>>>>>>> Measure, so will:
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> Quantity<Length> metre = Meansure.of(10, SI.METRE);
>
>>>>>>>
>
>>>>>>> Quantity<Length> foot = metre.to(US.FOOT);
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> WDYF?
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> --
>
>>>>>>>
>
>>>>>>> Otávio Gonçalves de Santana
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> blog: http://otaviosantana.blogspot.com.br/
>
>>>>>>>
>
>>>>>>> twitter: http://twitter.com/otaviojava
>
>>>>>>>
>
>>>>>>> site: *http://about.me/otaviojava <http://about.me/otaviojava>*
>
>>>>>>>
>
>>>>>>> 55 (11) 98255-3513
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> --
>
>>>>>>>
>
>>>>>>> Otávio Gonçalves de Santana
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> blog: http://otaviosantana.blogspot.com.br/
>
>>>>>>>
>
>>>>>>> twitter: http://twitter.com/otaviojava
>
>>>>>>>
>
>>>>>>> site: *http://about.me/otaviojava <http://about.me/otaviojava>*
>
>>>>>>>
>
>>>>>>> 55 (11) 98255-3513
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> --
>
>>>>>>>
>
>>>>>>> Otávio Gonçalves de Santana
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> blog: http://otaviosantana.blogspot.com.br/
>
>>>>>>>
>
>>>>>>> twitter: http://twitter.com/otaviojava
>
>>>>>>>
>
>>>>>>> site: *http://about.me/otaviojava <http://about.me/otaviojava>*
>
>>>>>>>
>
>>>>>>> 55 (11) 98255-3513
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> --
>
>>>>>>>
>
>>>>>>> Otávio Gonçalves de Santana
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>> blog: http://otaviosantana.blogspot.com.br/
>
>>>>>>>
>
>>>>>>> twitter: http://twitter.com/otaviojava
>
>>>>>>>
>
>>>>>>> site: *http://about.me/otaviojava <http://about.me/otaviojava>*
>
>>>>>>>
>
>>>>>>> 55 (11) 98255-3513
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>>
>
>>>>>>
>
>>>>>
>
>>>>
>
>>>>
>
>>>> --
>
>>>> It is not the strongest of the species that survives, nor the most
>
>>>> intelligent. It is the one that is most adaptable to change. - Darwin's
>
>>>> Origin of Species (digest)
>
>>>>
>
>>>
>
>>>
>
>>
>
>
>
>
>
> --
>
> It is not the strongest of the species that survives, nor the most
>
> intelligent. It is the one that is most adaptable to change. - Darwin's
>
> Origin of Species (digest)
>
>
>
--
Otávio Gonçalves de Santana
blog:
http://otaviosantana.blogspot.com.br/
twitter:
http://twitter.com/otaviojava
site: *
http://about.me/otaviojava <
http://about.me/otaviojava>*
55 (11) 98255-3513




