Akka Durable State 是通过持久化存储来保证可靠性的。在恢复保存的状态时，它需要从存储中重新读取数据并恢复系统的状态，以便在系统崩溃或故障的情况下能够正确地恢复，从而保证系统的稳定性和可靠性。

以下是一个示例，说明在 Akka 中使用持久化存储来实现 Durable State 恢复的方法：

import akka.actor.{Actor, ActorLogging, Props}
import akka.pattern.{Backoff, BackoffSupervisor}
import akka.persistence._

object MyStateActor {
  final case class MyState(data: String)

  def props(): Props = Props(new MyStateActor)
}

class MyStateActor extends PersistentActor with ActorLogging {
  import MyStateActor._

  override def persistenceId: String = "my-state-actor-id"

  var state: Option[MyState] = None

  override def receiveRecover: Receive = {
    case evt: MyState => state = Some(evt)
  }

  override def receiveCommand: Receive = {
    case MyStateActor.MyState(data) =>
      val evt = MyState(data)
      persist(evt) { persistedEvt =>
        state = Some(persistedEvt)
        log.info(s"State $persistedEvt persisted")
      }
    case "get-state" =>
      sender() ! state.toString
  }
}

object DurableStateRestoreExample extends App {
  val supervisorProps = BackoffSupervisor.props(
    Backoff.onFailure(
      MyStateActor.props(),
      childName = "my-state-actor",
      minBackoff = 3.seconds,
      maxBackoff = 30.seconds,
      randomFactor = 0.2
    )
  )

  val system = ActorSystem("durable-state-restore-example")
  val supervisor = system.actorOf(supervisorProps, "my-state-actor-supervisor")

  // use event sourcing to update the state
  supervisor ! MyStateActor.MyState("data 1")
  supervisor ! MyStateActor.MyState("data 2")

  // get the current state
  (supervisor