为工厂提供的童演员注入 Guice 服务答案

【问题标题】：Inject service with Guice to child actor provided by factory为工厂提供的童演员注入 Guice 服务
【发布时间】：2016-04-19 20:01:21
【问题描述】：

在我的应用程序中，我有一个创建一些工人的主管。这些工作人员中的每一个都需要两个 QueueClients 实例（具有不同的配置和工作人员之间的不同实例）。我是 guice 的新手，在将这些依赖项注入子演员时遇到了问题。

这是我的工人阶级：

object LegacyConsumer {

  trait Factory {
    def apply(): Actor
  }

}

class LegacyConsumer @Inject()(
  eventsClient: QueueClient,
  deadLetterClient: QueueClient
) extends Actor with ActorLogging {

  override def preStart(): Unit = {
    log.error("prestart")
    log.error(eventsClient.toString)
  }

  def receive: PartialFunction[Any, Unit] = {
    case _ =>
      log.error("received message consumer")
  }
}

如您所见，我需要两个 QueueClients 来构建：

trait QueueClient {
...

  def numMessages: Int
}

class SqsClient @Inject()(name: String, key: String, secret: String, zone: String) extends Logging with QueueClient {
...
}

这就是我尝试创建工人的方式

class LegacyConsumerSupervisor @Inject()(
  consumerFactory: LegacyConsumer.Factory,
  @Named("numWorkers") workers: Int
)
  extends Actor with ActorLogging with InjectedActorSupport {

  override def preStart(): Unit = {
    (1 to workers).foreach { workerNumber =>
      val key = s"WORKER-$workerNumber"
      injectedChild(consumerFactory(), key, _.withDispatcher("akka.legacy-consumer-dispatcher"))
    }
  }

最后这就是我的绑定的样子

class ChatModule extends AbstractModule with ScalaModule with AkkaGuiceSupport{
  override def configure() {
    bind[Actor].annotatedWith(Names.named(LegacyConsumerSupervisor.name)).to[LegacyConsumerSupervisor]

    bind(classOf[Int])
      .annotatedWith(Names named "numWorkers")
      .toInstance(ConfigurationHelper.getInt("chat.legacy.num-workers"))

    bindActorFactory[LegacyConsumer, LegacyConsumer.Factory]

    bind(classOf[QueueClient])
//      .annotatedWith(Names named "legacyEventsClient")
        .toInstance(
          new SqsClient(
            ConfigurationHelper.getString("chat.legacy.events.name"),
            ConfigurationHelper.getString("chat.legacy.events.key"),
            ConfigurationHelper.getString("chat.legacy.events.secret"),
            ConfigurationHelper.getString("chat.legacy.events.region")
          )
        )

    bind(classOf[QueueClient])
//      .annotatedWith(Names named "legacyDeadLetterClient")
        .toInstance(
          new SqsClient(
            ConfigurationHelper.getString("chat.legacy.dead-letter.name"),
            ConfigurationHelper.getString("chat.legacy.dead-letter.key"),
            ConfigurationHelper.getString("chat.legacy.dead-letter.secret"),
            ConfigurationHelper.getString("chat.legacy.dead-letter.region")
          )
        )
  }
}

如何将不同的队列客户端实例注入每个工作人员？所有 legacyEventsClients 和 legacyDeadLetterClients 具有相同的配置（基于类型安全配置）。解决方案是否与辅助注射有关？

我现在遇到的错误：

已经在 ...configure(ChatModule.scala:29) 处配置了与 ...QueueClient 的绑定。在 ...配置（ChatModule.scala:40）

所以我认为问题在于尝试将相同的绑定两次注入不同的实例...我尝试使用命名参数但随后将相同的客户端实例注入到每个 LegacyConsumer

问候

【问题讨论】：

标签： scala akka guice

【解决方案1】：

我终于做到了，并且成功了：

绑定：

    bind(classOf[QueueClient])
      .annotatedWith(Names named "legacyEventsClient")
      .toProvider(new Provider[SqsClient] {
        override def get = {
          new SqsClient(
            ConfigurationHelper.getString("chat.legacy.events.name"),
            ConfigurationHelper.getString("chat.legacy.events.key"),
            ConfigurationHelper.getString("chat.legacy.events.secret"),
            ConfigurationHelper.getString("chat.legacy.events.region")
          )
        }
      })

    bind(classOf[QueueClient])
      .annotatedWith(Names named "legacyDeadLetterClient")
      .toProvider(new Provider[SqsClient] {
        override def get = {
          new SqsClient(
            ConfigurationHelper.getString("chat.legacy.dead-letter.name"),
            ConfigurationHelper.getString("chat.legacy.dead-letter.key"),
            ConfigurationHelper.getString("chat.legacy.dead-letter.secret"),
            ConfigurationHelper.getString("chat.legacy.dead-letter.region")
          )
        }
      })

在我的工人阶级中：

class LegacyConsumer @Inject()(
  @Named("legacyEventsClient") eventsClient: QueueClient,
  @Named("legacyDeadLetterClient") deadLetterClient: QueueClient
) extends Actor with ActorLogging {

  override def preStart(): Unit = {
    log.error("prestart")
  }

  def receive: PartialFunction[Any, Unit] = {
    case _ =>
      log.error("received message consumer")
  }
}

【讨论】：