以下是一个示例代码，演示了如何在guardian actor中使用Akka AllForOne监督策略：

import akka.actor.{Actor, ActorLogging, ActorRef, ActorSystem, OneForOneStrategy, Props}
import akka.actor.SupervisorStrategy._
import scala.concurrent.duration._

class ChildActor extends Actor with ActorLogging {
  override def preStart(): Unit = {
    log.info("Child actor started")
  }
  
  override def postStop(): Unit = {
    log.info("Child actor stopped")
  }
  
  override def receive: Receive = {
    case "throwException" =>
      throw new Exception("Child actor failed")
    case _ =>
      log.info("Child actor received a message")
  }
}

class GuardianActor extends Actor with ActorLogging {
  override val supervisorStrategy: OneForOneStrategy = OneForOneStrategy(maxNrOfRetries = 10, withinTimeRange = 1 minute) {
    case _: Exception =>
      log.info("Restarting child actor")
      Restart
  }
  
  var childActor: ActorRef = _
  
  override def preStart(): Unit = {
    childActor = context.actorOf(Props[ChildActor], "childActor")
    log.info("Guardian actor started")
  }
  
  override def postStop(): Unit = {
    log.info("Guardian actor stopped")
  }
  
  override def receive: Receive = {
    case message =>
      childActor ! message
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val system = ActorSystem("SupervisionExample")
    val guardianActor = system.actorOf(Props[GuardianActor], "guardianActor")
    
    guardianActor ! "throwException"
    
    Thread.sleep(1000)
    
    system.terminate()
  }
}

在这个示例中，GuardianActor是一个顶级actor，它负责创建和监督ChildActor。GuardianActor的监督策略被设置为OneForOneStrategy，表示只有ChildActor失败时才会重启。

ChildActor具有一个简单的行为，当接收到"throwException"消息时，它会抛出一个异常。

在Main对象中，我们创建了一个ActorSystem和GuardianActor实例，然后向GuardianActor发送"throwException"消息。由于ChildActor抛出了异常，GuardianActor将根据监督策略进行重启。

请注意，这只是一个简单的示例，以演示如何在guardian actor中使用Akka AllForOne监督策略。实际应用中，您可能需要根据具体需求进行适当的修改和扩展。