从 Unit 到 Future[Boolean] 的类型转换

Question

我有以下功能，我想returnFuture[Boolean]但是IDE提示我returnUnit。我是 Scala 的新手。有人可以指出我做错了什么吗？

def remove(loginInfo: LoginInfo): Future[Boolean] = {
  val result = findObject(loginInfo)

  result.onSuccess {

    case Some(persistentPasswordInfo) =>

      val removeResult = remove(persistentPasswordInfo._id.toString)

      removeResult.map {
        case Left(ex) => Future.successful(false)
        case Right(b) => Future.successful(b)
      }
    case None => Future.successful(false)

  }

}

Answer 1

将 onSuccess 替换为 flatMap。假设您的 remove(x: String) 方法也 returns 一个 Future，那也需要 flatMapped:

def remove(loginInfo: LoginInfo): Future[Boolean] = {
  val result = findObject(loginInfo)

  result.flatMap {

    case Some(persistentPasswordInfo) =>

      val removeResult = remove(persistentPasswordInfo._id.toString)

      removeResult.flatMap {
        case Left(ex) => Future.successful(false)
        case Right(b) => Future.successful(b)
      }
    case None => Future.successful(false)

  }

}

从 Unit 到 Future[Boolean] 的类型转换

Type conversion from Unit to Future[Boolean]

scala

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