Scala 参与者在 Savings BankAccount 程序中的用例

Question

这不是任何类型的赋值。我正在学习Scala和Scala并发，最好是与AkkaActors一起学习。我这样做的方法之一是提出一些简单的程序设计，并尝试提出一个涉及应用于设计的Actors/并发性的实现：

我想编写的程序是一个储蓄银行账户应用程序，它有一个输入组件和一个输出组件
XYZ银行向客户提供开设储蓄账户的计划
1）要求客户ABC在开户时提供其个人详细信息
2）客户可以将钱存入他/她的账户吗
3）客户可以从他/她的账户中提款
4）如果账户余额低于100美元，则会通知客户。（例如，当客户从应用程序的输入屏幕中选择选项3时，他/她会被告知当时的账户余额低于100美元，因此无法提款，除非他们向其中存入更多的钱。）
5）应用程序应能够维护客户的交易历史，并显示交易历史（例如：当应用程序显示输入屏幕时，其中一个选项是-显示交易历史。当提示时选择该选项并附上数字时，应用程序应显示余额）
程序的输入部分由命令行上显示的4个选项组成：1。创建帐户2。存款3。提款。4.显示交易历史

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现在，我正在努力实现的是理解和识别：
1） 在这样的程序中，Akka actors/Scala并发库的用例是什么？该应用程序中的并发角色（如果有的话）是什么？
我最能利用哪些Scala集合库？

Answer 1

我希望这能解决问题：http://alexminnaar.com/introduction-to-the-multithreading-problem-and-the-akka-actor-solution.html

注意：我刚刚注意到这篇文章很旧。我将在2018年发布答案。

更新1:（来自链接的解释，在评论中提到）

这是多种可能策略中的一种方法。

有两个Actor使用

1. 银行账户-管理余额

       object WireTransfer {
       case class Transfer(from: ActorRef, to: ActorRef, amount: BigInt)
       case object Done
       case object Failed
       }
       //actor implementing the actions of a wire transfer between two bank account actors
       class WireTransfer extends Actor {
       import WireTransfer._
       def receive = LoggingReceive {
       //If Transfer message is received, send withdraw message to 'from' and wait for reply
       case Transfer(from, to, amount) =>
       from ! BankAccount.Withdraw(amount)
       context.become(awaitFrom(to, amount, sender))
       }
       //If Withdraw was successful, send deposit to other bank account actor, or else give them a failure message
       def awaitFrom(to: ActorRef, amount: BigInt, customer: ActorRef): Receive = LoggingReceive {
       case BankAccount.Done =>
       to ! BankAccount.Deposit(amount)
       context.become(awaitTo(customer))
       case BankAccount.Failed =>
       customer ! Failed
       context.stop(self)
       }
       //If deposit was successful, send 'Done' to original actor that sent Transfer message
       def awaitTo(customer: ActorRef): Receive = LoggingReceive {
       case BankAccount.Done =>
       customer ! Done
       context.stop(self)
       }
       }
   

2. WireTransfer-将余额从一个帐户转移到另一个帐户。

       object WireTransfer {
       case class Transfer(from: ActorRef, to: ActorRef, amount: BigInt)
       case object Done
       case object Failed
       }
       //actor implementing the actions of a wire transfer between two bank account actors
       class WireTransfer extends Actor {
       import WireTransfer._
       def receive = LoggingReceive {
       //If Transfer message is received, send withdraw message to 'from' and wait for reply
       case Transfer(from, to, amount) =>
       from ! BankAccount.Withdraw(amount)
       context.become(awaitFrom(to, amount, sender))
       }
       //If Withdraw was successful, send deposit to other bank account actor, or else give them a failure message
       def awaitFrom(to: ActorRef, amount: BigInt, customer: ActorRef): Receive = LoggingReceive {
       case BankAccount.Done =>
       to ! BankAccount.Deposit(amount)
       context.become(awaitTo(customer))
       case BankAccount.Failed =>
       customer ! Failed
       context.stop(self)
       }
       //If deposit was successful, send 'Done' to original actor that sent Transfer message
       def awaitTo(customer: ActorRef): Receive = LoggingReceive {
       case BankAccount.Done =>
       customer ! Done
       context.stop(self)
       }
       }