public class Foo {
@Inject
private Instance<Bar> barInstance;
private Bar theBar;
@PostConstruct
private void init() {
thebar = barInstance......get();
}
}
Romain Manni-Bucau
@rmannibucau
http://www.tomitribe.com
http://rmannibucau.wordpress.com
https://github.com/rmannibucau
2014-11-17 13:23 GMT+01:00 Lars-Fredrik Smedberg <[email protected]>:
> Hi Romain
>
> When you say "cache the result in another bean" could you give an example?
> I'm not sure exactly what you mean and if its applicable in our case.
>
> Regards
> LF
>
> On Mon, Nov 17, 2014 at 12:03 PM, Romain Manni-Bucau <[email protected]>
> wrote:
>>
>> Hi
>>
>> both will have the same perf more or less. I recommand you to cache
>> the result in another bean if you care since it can be expensive if
>> done by request.
>>
>> About the algorithm you can have a look to
>> org.apache.webbeans.container.InjectionResolver#implResolveByType(...).
>> Mainly loop over all beans and keep the ones matching the required
>> type. Then we select by qualifier.
>>
>>
>>
>> Romain Manni-Bucau
>> @rmannibucau
>> http://www.tomitribe.com
>> http://rmannibucau.wordpress.com
>> https://github.com/rmannibucau
>>
>>
>> 2014-11-17 12:00 GMT+01:00 Lars-Fredrik Smedberg <[email protected]>:
>> > Hi Mark
>> >
>> > Thanks for your reply, we use the BeanProvider approach for Wink and a
>> > custom UserHandleFactory (since WebSphere 8.5.5 uses Wink) since Wink
>> > creates the factory using new.
>> >
>> > Can you explain how the getBeans lookup works in BeanProvider works?
>> > Also
>> > performance wise which is the best would you say? Provider<...> or
>> > BeanProvider?
>> >
>> > Regards
>> > LF
>> >
>> > On Nov 17, 2014 11:23 AM, "Mark Struberg" <[email protected]> wrote:
>> >>
>> >> Hi Lars-Fredrik!
>> >>
>> >>
>> >> The biggest benefit of DeltaSpike BeanProvider is that it uses
>> >> BeanManagerProvider to get the BeanManager. This is really cool if you
>> >> do
>> >> NOT have access to the BeanManager at first hand. E.g. if you are in
>> >> places
>> >> where there is no injection available by default, e.g. in a JPA-2.0
>> >> EntityListener.
>> >>
>> >> The get-me-the-instance-from-the-beanmanager part of DeltaSpike is
>> >> pretty
>> >> much the same like with Instance<T>.
>> >> How do testimpl1 and testimpl2 look like? You could even @Inject those
>> >> directly. If this is more dynamic then use @Inject Instance<Test>
>> >> provider;
>> >> for them. Instance extends Provider and adds the ability to dynamically
>> >> iterate over them, etc.
>> >>
>> >> LieGrue,
>> >> strub
>> >>
>> >>
>> >>
>> >> >________________________________
>> >> > From: Lars-Fredrik Smedberg <[email protected]>
>> >> >To: "[email protected]" <[email protected]>
>> >> >Sent: Monday, 17 November 2014, 9:36
>> >> >Subject: Performance/design question
>> >> >
>> >> >
>> >> >
>> >> >Hi!
>> >> >
>> >> >
>> >> >We have a @Produces method that produces dependent CDI beans. The
>> >> > objects
>> >> > we produce are depenend since we need to use InjectionPoint to get to
>> >> > the
>> >> > annotations at the injection point.
>> >> >
>> >> >
>> >> >Depending on which annotations are present and their attribute values
>> >> > we
>> >> > choose which implementation to return.
>> >> >
>> >> >
>> >> >Pseudocode, TestImpl1/2 both implement Test ofcourse, we use
>> >> > Provider<...> since we do not want to init both 1 and 2 when we only
>> >> > will
>> >> > return one of them. The implementations both injects other beans,
>> >> > thats why
>> >> > we not create them using "new".
>> >> >
>> >> >
>> >> >@Produces
>> >> >public static Test createTest(Provider<TestImpl1> testImpl1,
>> >> > Provider<TestImpl2> testImpl2, InjectionPoint injectionPoint) {
>> >> >
>> >> >
>> >> > if
>> >> >
>> >> > (injectionPoint.getAnnotated().getAnnotation(TestAnnotation.class).getAttribute().equals(....))
>> >> > {
>> >> > return testImpl1.get();
>> >> > }
>> >> >
>> >> > else {
>> >> > return testImpl2.get();
>> >> > }
>> >> >}
>> >> >
>> >> >
>> >> >
>> >> >Question:
>> >> >
>> >> >
>> >> >1. What is the overhead of using the above approach with Provider<...>
>> >> > and get() on the implementation we eventually will use compared to
>> >> > e.g.
>> >> > DeltaSpikes BeanProvider.getContextualReference ?
>> >> >2. In OWB can someone explain the process that OWB uses internally
>> >> > when
>> >> > getBeans() is called?
>> >> >
>> >> >
>> >> >Regards
>> >> >LF
>> >> >
>> >> >--
>> >> >
>> >> >Med vänlig hälsning / Best regards
>> >> >
>> >> >Lars-Fredrik Smedberg
>> >> >
>> >> >STATEMENT OF CONFIDENTIALITY:
>> >> >The information contained in this electronic message and any
>> >> >attachments to this message are intended for the exclusive use of the
>> >> >address(es) and may contain confidential or privileged information. If
>> >> >you are not the intended recipient, please notify Lars-Fredrik
>> >> > Smedberg
>> >> >immediately at [email protected], and destroy all copies of this
>> >> >message and any attachments.
>> >> >
>> >> >
>
>
>
>
> --
> Med vänlig hälsning / Best regards
>
> Lars-Fredrik Smedberg
>
> STATEMENT OF CONFIDENTIALITY:
> The information contained in this electronic message and any
> attachments to this message are intended for the exclusive use of the
> address(es) and may contain confidential or privileged information. If
> you are not the intended recipient, please notify Lars-Fredrik Smedberg
> immediately at [email protected], and destroy all copies of this
> message and any attachments.
