訪問的ExecutionContext

Question

我有這樣的特質

trait NonBlockingGoodness extends DataStore { 
    import akka.dispatch.{ Future, ExecutionContext } 
    import akka.util.duration._ 
    import akka.util.Timeout 

    implicit val ec = ExecutionContext.fromExecutorService(yourExecutorServiceGoesHere) 
    implicit lazy val timeout = Timeout(5 seconds)  
} 

我想訪問ExecutionContext在另一個特質像這樣

trait AsyncGoodness extends NonBlockingGoodness { 
    import akka.dispatch.Future 

    def doSomething = { 
    Future { "Future is the bomb." } 
    } 

不過，我得到錯誤

Could not find implicit value for parameter executor: akka.dispatch.ExecutionContext 

已更新： 我想出了h ow得到ExecutionContext範圍內

trait AsyncGoodness extends NonBlockingGoodness { 
    import akka.dispatch.ExecutionContext 
    import akka.dispatch.Future 

    def doSomething()(implicit executor: ExecutionContext) = { 
    Future { "Future is the bomb." } 
    } 

但是，我有一個後續問題。由於我可能在AsyncGoodness中使用ExecutionContext以上的一種以上方法，有沒有辦法將它傳遞到trait級別，而不是像上面我做的那樣在每個方法上傳遞它。

Answer 1

事實證明，我需要做的就是明確指定ec返回類型爲編譯器使用它。這裏的工作代碼

trait NonBlockingGoodness extends DataStore { 
    import akka.dispatch.{ Future, ExecutionContext } 
    import akka.util.duration._ 
    import akka.util.Timeout 

    implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(yourExecutorServiceGoesHere) 
    implicit lazy val timeout = Timeout(5 seconds)  
} 

trait AsyncGoodness extends NonBlockingGoodness { 
    import akka.dispatch.Future 

    def doSomething = { 
    Future { "Future is the bomb." } 
    } 

Answer 2

我知道你不必再導入任何東西，但是這樣的東西應該適合你。

trait NonBlockingGoodness { 
    import scala.concurrent.{ Future, ExecutionContext } 
    import scala.concurrent.util.duration._ 
    import akka.util.Timeout 

    object Implicit { 
    implicit val ec = ExecutionContext.Implicits.global 
    implicit lazy val timeout = Timeout(5 seconds) 
    } 

} 

trait AsyncGoodness extends NonBlockingGoodness { 
    import scala.concurrent.Future 
    import Implicit._ 
    def doSomething = { 
    Future { "Future is the bomb." } 
    } 
}