Akka/Scala example source code file (SettingsExtensionDocSpec.scala)

This example Akka source code file (SettingsExtensionDocSpec.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, actorsystem, akka, concurrent, duration, extension, extensionid, myactor, scala, settings, settingsextensiondocspec, settingsimpl, string, test, testing, time

The SettingsExtensionDocSpec.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package docs.extension

//#imports
import akka.actor.ActorSystem
import akka.actor.Extension
import akka.actor.ExtensionId
import akka.actor.ExtensionIdProvider
import akka.actor.ExtendedActorSystem
import scala.concurrent.duration.Duration
import com.typesafe.config.Config
import java.util.concurrent.TimeUnit

//#imports

import akka.actor.Actor
import akka.testkit.AkkaSpec

//#extension
class SettingsImpl(config: Config) extends Extension {
  val DbUri: String = config.getString("myapp.db.uri")
  val CircuitBreakerTimeout: Duration =
    Duration(config.getMilliseconds("myapp.circuit-breaker.timeout"),
      TimeUnit.MILLISECONDS)
}
//#extension

//#extensionid
object Settings extends ExtensionId[SettingsImpl] with ExtensionIdProvider {

  override def lookup = Settings

  override def createExtension(system: ExtendedActorSystem) =
    new SettingsImpl(system.settings.config)

  /**
   * Java API: retrieve the Settings extension for the given system.
   */
  override def get(system: ActorSystem): SettingsImpl = super.get(system)
}
//#extensionid

object SettingsExtensionDocSpec {

  val config = """
    //#config
    myapp {
      db {
        uri = "mongodb://example1.com:27017,example2.com:27017"
      }
      circuit-breaker {
        timeout = 30 seconds
      }
    }
    //#config
    """

  //#extension-usage-actor

  class MyActor extends Actor {
    val settings = Settings(context.system)
    val connection = connect(settings.DbUri, settings.CircuitBreakerTimeout)

    //#extension-usage-actor
    def receive = {
      case someMessage =>
    }

    def connect(dbUri: String, circuitBreakerTimeout: Duration) = {
      "dummy"
    }
  }

}

class SettingsExtensionDocSpec extends AkkaSpec(SettingsExtensionDocSpec.config) {

  "demonstrate how to create application specific settings extension in Scala" in {
    //#extension-usage
    val dbUri = Settings(system).DbUri
    val circuitBreakerTimeout = Settings(system).CircuitBreakerTimeout
    //#extension-usage
  }

}