Your answer is perfect! If you do not like to have EJB's @DependsOn annotation, we could make it more usable for EJBs :-)
You are right -> it looks ugly. For CDI we will have to consider the types AND qualifiers...
thanks!,
adam
On 12.09.2011, at 15:47, Pete Muir wrote:
> The issue with @DependsOn for CDI is that specifying a CDI dependency using an annotation is extremely ugly. Say I have a CDI bean:
>
> @Colored @Red
> class Parrot {
>
> }
>
> If I wanted to depend on that using @DependsOn:
>
> @DependsOn(type=Parrot.class, qualifiers={Colored.class, Red.class})
>
> it's pretty nasty. We're not going to win anyone to Java EE with this.
>
> However it get's worse.
>
> @British @Gender(MALE)
> class Person {
>
> }
>
> @DependsOn(type=Person.class, qualifiers={_at_DependentQualifier(British.class), @DependentQualifier(value=Gender.class, attributes={_at_DependentQualifierAttribute(name="value", value="MALE")}))
>
> This is now basically useless, and I've yet to hear anyone say that this is a good approach.
>
> I know that some people have proposed requiring this only works with @Named e.g.
>
> @British @Gender(MALE)
> @Named("britishMalePerson")
> class Person {
>
> }
>
> @DependsOn("britishMalePerson")
>
> However this cannot be included in the CDI spec as it is a complete deviation from the guiding principles of CDI.
>
> I've yet to see a better approach - any ideas? :-D
>
> Pete
>
> On 12 Sep 2011, at 04:13, Antonio Goncalves wrote:
>
>> Wouldn't it also make sense to have @DependsOn on some CDI beans (@ApplicationScoped for example) ?
>>
>>
>> On Sat, Sep 10, 2011 at 06:25, Reza Rahman <reza_rahman_at_lycos.com> wrote:
>> Adam,
>>
>> I hate to say this, but I'd rather focus on moving @DependsOn to CDI where name-based qualifiers would be unlikely to be used anyway.
>>
>> Cheers,
>> Reza
>>
>>
>>
>> On 9/9/2011 7:23 PM, Marina Vatkina wrote:
>> Adam,
>>
>> What would be the use-case for the new element?
>>
>> thanks,
>> -marina
>>
>> Adam Bien wrote:
>> Hi All,
>>
>> currently the @DependsOn annotation looks like:
>> @Target(value = {ElementType.TYPE})
>> @Retention(value = RetentionPolicy.RUNTIME)
>> public @interface DependsOn {
>>
>> public String[] value();
>> }
>>
>>
>> I would like to extend it with a class element:
>>
>> @Target(value = {ElementType.TYPE})
>> @Retention(value = RetentionPolicy.RUNTIME)
>> public @interface DependsOn {
>>
>> public String[] value();
>> *public Class[] classes() default void.class;*
>> }
>>
>> It should be possible to specify the dependencies as simple EJB-names as well as referring directly to the classes,
>>
>> any thoughts?
>>
>> adam
>>
>>
>>
>>
>>
>>
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>>
>>
>>
>>
>>
>> --
>> Antonio Goncalves
>> Software architect and Java Champion
>>
>> Web site | Twitter | Blog | LinkedIn | Paris JUG
>
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