Scala中的DropWizard/Jersey/HK2依赖注入

Question

试图创建一个自定义的@context，我可以通过Jersey注入到我的资源中。

这在本问题的Java中有涉及。我已经阅读了有关这方面的文档，这些文档也是用Java编写的。最后，GitHub中的一些代码涵盖了相同的主题（通过Dropwizard完成）。

import org.glassfish.hk2.api.Factory
import javax.inject.Inject
import javax.ws.rs.container.ContainerRequestContext
import MyObj

class MyObjFactory @Inject()(ctr: ContainerRequestContext) extends Factory[MyObj] {
  private final val context: ContainerRequestContext = ctr

  override def provide(): MyObj = context.getProperty("myObj").asInstanceOf[MyObj]

  override def dispose(myObj: MyObj): Unit = { }
}

import org.glassfish.hk2.utilities.binding.AbstractBinder

environment.jersey.register(new AbstractBinder {
  override def configure(): Unit = {
    bindFactory(classOf[MyObjFactory])
        .to(classOf[MyObj])
        .proxy(true)
        .proxyForSameScope(false)
        .in(classOf[RequestScoped])
  }
})

@Path("/")
class MyResource {
    @GET
    def get(@Context uriInfo: UriInfo, @Context myObjFactory: MyObjFactory) = {
        // do stuff
    }
}

这将全部编译，但在运行时失败，出现以下异常

ERROR [2017-04-05 00:26:14,605] io.dropwizard.jersey.errors.LoggingExceptionMapper: Error handling a request: 8e5877857c823fef
! java.lang.IllegalArgumentException: Invalid injectee with required type of null passed to getInjecteeDescriptor
! ... 87 common frames omitted
! Causing: org.glassfish.hk2.api.MultiException: A MultiException has 1 exceptions.  They are:
! 1. java.lang.IllegalArgumentException: Invalid injectee with required type of null passed to getInjecteeDescriptor
! 
! at org.jvnet.hk2.internal.ServiceLocatorImpl.internalGetInjecteeDescriptor(ServiceLocatorImpl.java:545)
! at org.jvnet.hk2.internal.ServiceLocatorImpl.getInjecteeDescriptor(ServiceLocatorImpl.java:584)
! at org.glassfish.jersey.internal.inject.ContextInjectionResolver$1.compute(ContextInjectionResolver.java:102)
! at org.glassfish.jersey.internal.inject.ContextInjectionResolver$1.compute(ContextInjectionResolver.java:98)
! at org.glassfish.hk2.utilities.cache.Cache$OriginThreadAwareFuture$1.call(Cache.java:97)

我不知道是我在向Scala的转换中犯了错误，还是我在注册绑定器时做了错误的事情。

Answer 1

get(@Context uriInfo: UriInfo, @Context myObjFactory: MyObjFactory) <===

您正在尝试注入工厂。工厂用于创建服务。在这种情况下不是要注射的。您要注入的是实际的服务，工厂将用于在幕后创建它

get(@Context uriInfo: UriInfo, @Context myOb: MyObj) <===