我使用Finagle作为Web服务器,我想从我的应用程序逻辑返回Scala-Futures。如何以一种非阻塞的方式将scala.concurrent.Future转换为com.twitter.util.Future?
答案 0 :(得分:20)
没有足够的环境来测试这个,但这是我为"com.twitter" %% "finagle-http" % "6.25.0"
撰写的内容:
import com.twitter.{util => twitter}
import scala.concurrent.{ExecutionContext, Promise, Future}
import scala.util.{Failure, Success, Try}
import language.implicitConversions
object TwitterConverters {
implicit def scalaToTwitterTry[T](t: Try[T]): twitter.Try[T] = t match {
case Success(r) => twitter.Return(r)
case Failure(ex) => twitter.Throw(ex)
}
implicit def twitterToScalaTry[T](t: twitter.Try[T]): Try[T] = t match {
case twitter.Return(r) => Success(r)
case twitter.Throw(ex) => Failure(ex)
}
implicit def scalaToTwitterFuture[T](f: Future[T])(implicit ec: ExecutionContext): twitter.Future[T] = {
val promise = twitter.Promise[T]()
f.onComplete(promise update _)
promise
}
implicit def twitterToScalaFuture[T](f: twitter.Future[T]): Future[T] = {
val promise = Promise[T]()
f.respond(promise complete _)
promise.future
}
}
答案 1 :(得分:14)
也可以使用Twitter投影库:https://github.com/twitter/bijection
即com.twitter.bijection.twitter_util.UtilBijections
(https://github.com/twitter/bijection/blob/develop/bijection-util/src/main/scala/com/twitter/bijection/twitter_util/UtilBijections.scala)
此库处理重要细节,例如,如果您前后转换对象,它只需解开原始对象。
答案 2 :(得分:7)
以下是使用twitter双向库的示例:
import scala.concurrent.{Future => ScalaFuture}
import com.twitter.util.{Future => TwitterFuture}
// extend values by adding the conversion method "as"
import com.twitter.bijection.Conversion.asMethod
// pull in various implicit converters that "as" expects,
// including twitter2ScalaFuture:
import com.twitter.bijection.twitter_util.UtilBijections._
def doSomething: ScalaFuture[T] = {
val response: TwitterFuture[T] = ???
response.as[ScalaFuture[T]]
}