I am concerned about #2 as it lookup is more dynamic than injection. Be
careful while making #2, else we may cause some unnecessary loading.
On Wednesday 08 February 2012 12:56 PM, Mahesh.Kannan_at_Oracle.Com wrote:
> Hi All,
>
> The HK2 team (Tom Beerbower, John Wells, Mason Taube, Larry Feigen
> & myself) went to asarch last week to
> discuss about some of the changes to hk2 that we had been discussing
> for a while. Some of the ideas were
> initiated by Jerome & Jeff Trent.
>
> While the HK2 team is yet to present the full set of changes to the
> asarch (which we will do so in about a couple
> of weeks from now), it was agreed that, to start with, GlassFish
> modules should move away from using non
> standard Classes like Habitat and use standards based annotations and
> classes as specified by jsr 330
> (javax.inject.Inject, javax.inject.Provider etc.). To quote Jerome:
> "Classes like Habitat exposes too many APIs
> available to the users that makes the hk2 evolution very difficult.
> " Also some of the APIs are unclear (when to
> use habitat.getComponent() versus habitat.getByType()
> /habitat.getByContract() ).
>
> So, the first step is to move away from Habitat (where ever
> possible) and use jsr 330 interface and annotations.
>
> In order to do this, the hk2 team will be making the following
> changes to the GlassFish modules.
>
> 1. Move away from org.jvnet.hk2.annotations.Inject to javax.inject.Inject
> 1.1 We will convert @org.jvnet.hk2.annotations.Inject Foo foo
> to @javax.inject.Inject
> Foo foo;
> 1.2 We will convert
> @org.jvnet.hk2.annotations.Inject(name="foo") Foo foo
> to @javax.inject.Inject
> @javax.inject.Named("foo")
> Foo foo;
> 1.3 We will convert
> @org.jvnet.hk2.annotations.Inject(optional=true) Foo foo
> to @javax.inject.Inject
> @org.jvnet.hk2.annotations.Optional
> Foo foo;
> 1.3 We will convert
> @org.jvnet.hk2.annotations.Inject(name="foo", option=true) Foo foo
> to @javax.inject.Inject
> @javax.inject.Named("foo")
> @org.jvnet.hk2.annotations.Optional
> Foo foo;
>
> 2. If we find that a class injects Habitat (or Services) and uses
> habitat.getByContract(Foo.class) or
> service.forContract(Foo.class).get(), then we will do the following:
> 2.1 Introduce a new injection:
> @javax.inject.Inject
> javax.inject.Provider<Foo> fooProvider;
> and 2.2 replace the getBycontract() / forContract() calls with:
> fooProvider.get();
>
> 3. If we find that a class
> a) implements PostConstruct,
> b) injects Habitat (or Services) and
> c) uses habitat.getByContract(Foo.class) or
> services.forContract(Foo.class).get()*in the postConstruct
> method, *then we will do the following:
> 3.1 replace the getBycontract() / forConttract() calls with:
> @javax.inject.Inject Foo foo;
> 3.2 Obviously, we will talk to the module owner to find out why
> the injection was not made in the first place.
>
>
> Note: *The Hk2 team will be making the above changes and will reach
> out to the module owners to find out what tests (dev tests, QL etc.)
> need to be run before committing the changes.*
>
> Please let us know if you have any questions / concerns.
>
> Thanks
> Hk2 team
>