Illustrates a POJO API on top of Config

AkkaConfigBean.scala

package akka.config.bean

import java.util.{ List ⇒ JList }
import java.util.{ ArrayList ⇒ JArrayList }
import java.util.{ HashMap ⇒ JHashMap }
import scala.reflect.BeanProperty
import com.typesafe.config.Config
import com.typesafe.config.ConfigFactory

class AkkaConfigBean {

  @BeanProperty
  var loglevel: String = _

  @BeanProperty
  var eventHandlers: JList[String] = new JArrayList

  @BeanProperty
  var daemonic: java.lang.Boolean = _

  @BeanProperty
  var dispatchers: JList[DispatcherConfigBean] = new JArrayList

  @BeanProperty
  var remote: RemoteConfigBean = _

  def toConfig(): Config = {
    import scala.collection.JavaConverters._
    val m = new JHashMap[String, Any]
    if (loglevel ne null) m.put("akka.loglevel", loglevel)
    if (!eventHandlers.isEmpty) m.put("akka.event-handlers", eventHandlers)
    if (daemonic ne null) m.put("akka.daemonic", daemonic)
    for (d ← dispatchers.asScala) d.toConfig(m)
    if (remote ne null) remote.toConfig(m)

    ConfigFactory.parseMap(m)
  }

  override def toString(): String = toConfig.root.render

}

class DispatcherConfigBean(dispatcherId: String) {

  def this() {
    this("akka.actor.default-dispatcher")
  }

  @BeanProperty
  var dispatcherType: String = _

  @BeanProperty
  var executor: ExecutorConfigBean = _

  def toConfig(m: JHashMap[String, Any]): Unit = {
    if (dispatcherType ne null) m.put(dispatcherId + ".type", dispatcherType)
    if (executor ne null) executor.toConfig(dispatcherId, m)
  }

}

trait ExecutorConfigBean {
  def toConfig(dispatcherId: String, m: JHashMap[String, Any]): Unit
}

class ForkJoinExecutorConfigBean extends ExecutorConfigBean {
  @BeanProperty
  var parallelismMin: java.lang.Integer = _

  @BeanProperty
  var parallelismFactor: java.lang.Double = _

  @BeanProperty
  var parallelismMax: java.lang.Integer = _

  def toConfig(dispatcherId: String, m: JHashMap[String, Any]): Unit = {
    m.put(dispatcherId + ".executor", "fork-join-executor")
    if (parallelismMin ne null) m.put(dispatcherId + ".fork-join-executor.parallelism-min", parallelismMin)
    if (parallelismFactor ne null) m.put(dispatcherId + ".fork-join-executor.parallelism-factor", parallelismFactor)
    if (parallelismMax ne null) m.put(dispatcherId + ".fork-join-executor.parallelism-max", parallelismMax)
  }
}

class ThreadPoolExecutorConfigBean extends ExecutorConfigBean {
  @BeanProperty
  var corePoolSizeMin: java.lang.Integer = _

  @BeanProperty
  var corePoolSizeFactor: java.lang.Double = _

  @BeanProperty
  var corePoolSizeMax: java.lang.Integer = _

  @BeanProperty
  var keepAliveTime: String = _

  def toConfig(dispatcherId: String, m: JHashMap[String, Any]): Unit = {
    m.put(dispatcherId + ".executor", "thread-pool-executor")
    if (corePoolSizeMin ne null) m.put(dispatcherId + ".thread-pool-executor.parallelism-min", corePoolSizeMin)
    if (corePoolSizeFactor ne null) m.put(dispatcherId + ".thread-pool-executor.parallelism-factor", corePoolSizeFactor)
    if (corePoolSizeMax ne null) m.put(dispatcherId + ".thread-pool-executor.parallelism-max", corePoolSizeMax)
    if (keepAliveTime ne null) m.put(dispatcherId + ".thread-pool-executor.keep-alive-time", keepAliveTime)
  }
}

class RemoteConfigBean {
  @BeanProperty
  var hostname: String = _

  @BeanProperty
  var port: java.lang.Integer = _

  def toConfig(m: JHashMap[String, Any]): Unit = {
    if (hostname ne null) m.put("akka.remote.netty.hostname", hostname)
    if (port ne null) m.put("akka.remote.netty.port", port)
  }
}