scala - 对scala使用局部函数来捕获 block

Question

我有一个catch块，最后我重复了很多次，发现这个SO问题确认了我可以将部分函数用作catch块(Scala 2.9的try…catch概括化的用例是什么？1) 。

目前，我的代码如下所示:

var task = newTask("update product", "update for customer " + customerId.toString)
try {
          val vcdRouter = actorSystem.actorFor("user/supervisor/router-10.10.10.10:443")

          val vdcId = new UUID("92ddba5e-8101-4580-b9a5-e3ee6ea5718f")
          val vdcGet = sendExpect[AdminVdcType](vcdRouter, GetVdc(vdcId))
          val vdcPut = VdcPutConfig(vdcGet, c)
          val vdcPutTask = sendExpect[TaskType](vcdRouter, UpdateVdc(vdcId, vdcPut))

          task = task.copy(Progress = 100, status = SuccessType)

        } catch {
          case failure: NoResponseBodyException =>
            logger.debug("*** In putCustomerProduct, got a Left(VcdGatewayException)")
            task = task.copy(Progress = 100, status = Error, Error = Option(exceptionToError(failure, BadGateway)))

          case failure: VcdGatewayException ⇒
            logger.debug("*** In putCustomerProduct, got a Left(VcdGatewayException)")
            task = task.copy(Progress = 100, status = Error, Error = Option(exceptionToError(failure, GatewayTimeout)))

          case failure: Exception ⇒
            logger.debug("*** In putCustomerProduct, got a Left(Exception)")
            task = task.copy(Progress = 100, status = Error, Error = Option(exceptionToError(failure)))

        }

由于我有在catch块内更改的任务var，是否有一种很好的方法可以从保存catch块的部分函数中对其进行访问？该任务是一个变量，因为它在进入系统后会设置一些初始化数据，例如创建的时间戳。我可以解决此问题，但是无论如何我都希望对原始问题的答案感兴趣。

Answer 1

我假设您要使用几个具有不同var task的不同函数。

您可以创建一个同时使用task和任务设置程序作为参数的函数，该函数返回可以用作捕获处理程序的PartialFunction。

def handler(task: Task, setTask: Task => Any): PartialFunction[Throwable, Any] = {
  case failure: NoResponseBodyException =>
    logger.debug("*** In putCustomerProduct, got a Left(NoResponseBodyException)")
    setTask(task.copy(Progress = 100, status = Error, Error = Option(exceptionToError(failure, BadGateway))))

  case failure: VcdGatewayException =>
    logger.debug("*** In putCustomerProduct, got a Left(VcdGatewayException)")
    setTask(task.copy(Progress = 100, status = Error, Error = Option(exceptionToError(failure, GatewayTimeout))))

  case failure: Exception =>
    logger.debug("*** In putCustomerProduct, got a Left(Exception)")
    setTask(task.copy(Progress = 100, status = Error, Error = Option(exceptionToError(failure))))
}

// somewhere else in your code...
var task = newTask("update product", "update for customer " + customerId.toString)
try {
   val vcdRouter = actorSystem.actorFor("user/supervisor/router-10.10.10.10:443")

  val vdcId = new UUID("92ddba5e-8101-4580-b9a5-e3ee6ea5718f")
  val vdcGet = sendExpect[AdminVdcType](vcdRouter, GetVdc(vdcId))
  val vdcPut = VdcPutConfig(vdcGet, c)
  val vdcPutTask = sendExpect[TaskType](vcdRouter, UpdateVdc(vdcId, vdcPut))

  task = task.copy(Progress = 100, status = SuccessType)
} catch handler(task, task = _)

我也同意 user3001，您应该尝试减少catch处理程序中的重复项。