Scala和Spring -棘手的案子？

Question

我想使用factory-method用Spring实例化一个bean。但是，诀窍是我想要访问工厂方法中的当前ApplicationContext。

下面是我尝试过的代码：

object ActorSystemFactory {

  var applicationContext: ApplicationContext = _

  def createActorSystem = {
    val system = ActorSystem("AkkaScalaSpring")
    SpringExtensionImpl(system)(applicationContext) //need applicationContext here
    system
  }
}

class ActorSystemFactory extends ApplicationContextAware {

  //Spring warns that createActorSystem does not exist here!! and it is...right
  //Indeed, it is present in the companion object to make it "static" equivalent.    

  def setApplicationContext(applicationContext: ApplicationContext) {
    ActorSystemFactory.applicationContext = applicationContext
  }

}

我的xml声明：

<bean id="actorSystem" class="com.myPackage.ActorSystemFactory" factory-method="createActorSystem">
</bean>

对于ActorSystemFactory类中的注释，如何处理？

Answer 1

好吧，所以我成功做到了。

实际上，现在我不使用静态工厂方法技术，而是使用实例工厂方法技术：

class ActorSystemFactory extends ApplicationContextAware {

  def createActorSystem = {
    val system = ActorSystem("AkkaScalaSpring")
    SpringExtensionImpl(system)
    system
  }

  def setApplicationContext(applicationContext: ApplicationContext) {
    ActorSystemFactory.applicationContext = applicationContext
  }
}

object ActorSystemFactory {

  var applicationContext: ApplicationContext = _

}



<bean id="actorSystemFactory" class="myPackage.ActorSystemFactory"/>

<bean id="actorSystem" factory-bean="actorSystemFactory" factory-method="createActorSystem" />

(http://docs.spring.io/spring/docs/3.0.x/reference/beans.html) (不管Spring的版本是什么)

整个工程按预期进行。

Answer 2

缺省情况下，spring是单例的。您可以在类中直接实例化参与者系统，而不需要对象。