HK2 annotations not being handled

问题:

I'm using HK2 through Jersey, and am looking to get @Immediate services working. In the process, I notice that (as it seems) none of the annotations for my services are getting registered. E.g., after spinning up my ServiceLocator and looking at my descriptor for a service annotated with @Singleton, it is still set as @PerLookup. My code for initiating my application handler is below:

ApplicationHandler handler = new ApplicationHandler(resourceConfig, new AbstractBinder() { ... });

My binder registers a service like so:

bindAsContract(ShouldHaveSingletonScope.class);

Looking at my ServiceLocator immediately after this, I see that the scope is not being pulled from the class (still @PerLookup). Is there something additional I need to specify to tell HK2 to parse class annotations? This seems like a pretty standard use case so I must be missing something.

回答1:

There is a method on ServiceLocatorUtilities called addClasses

So get access to the ServiceLocator and just do

ServiceLocatorUtilities.addClasses(locator, ShouldHaveSingletonScope.class);

The binders are very literal, and will only do what you tell it as opposed to looking at the classes directly.

回答2:

This should work:

bindAsContract(ShouldHaveSingletonScope.class).in(Singleton.class);

You can either configure the locator manually using Binder

-or-

use hk2 annotations, run hk2-inhabitants-generator (see hk2 doc) which will generate META-INF/hk2-locator/default file, then you will need to create your own ComponentProvider (see jersey doc) to populate service locator from that.