Finch Hello World错误: Http不是com.twitter.finagle的成员

Question

我正在尝试使用scala finch库来构建一个API。

我有以下简单的代码：

package example

import io.finch._
import com.twitter.finagle.Http

object HelloWorld extends App {

  val api: Endpoint[String] = get("hello") { Ok("Hello, World!") }

  Http.serve(":8080", api.toService)
}

和一个如下所示的build.sbt文件：

name := "hello-finch"

version := "1.0"

scalaVersion := "2.10.6"

mainClass in (Compile, run) := Some("example.HelloWorld")

libraryDependencies ++= Seq(
  "com.github.finagle" %% "finch-core" % "0.10.0"
)

// found here: https://github.com/finagle/finch/issues/604
addCompilerPlugin(
  "org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full
)

当我编译和运行代码时，我得到了这个错误消息：

object Http is not a member of package com.twitter.finagle
[error] import com.twitter.finagle.Http
[error]        ^
[error] /Users/jamesk/Code/hello_finch/hello-finch/src/main/scala/example/Hello.scala:8: wrong number of type arguments for io.finch.Endpoint, should be 2
[error]   val api: Endpoint[String] = get("hello") { Ok("Hello, World!") }
[error]            ^
[error] /Users/jamesk/Code/hello_finch/hello-finch/src/main/scala/example/Hello.scala:8: not found: value get
[error]   val api: Endpoint[String] = get("hello") { Ok("Hello, World!") }
[error]                               ^
[error] /Users/jamesk/Code/hello_finch/hello-finch/src/main/scala/example/Hello.scala:10: not found: value Http
[error]   Http.serve(":8080", api.toService)
[error]   ^
[error] four errors found
[error] (compile:compileIncremental) Compilation failed
[error] Total time: 1 s, completed Aug 15, 2017 12:56:01 PM

在这一点上，我已经没有想法了，它看起来是一个很好的库，但让它工作是一件痛苦的事情。任何帮助都将不胜感激。

Answer 1

我已经更新了您的示例以使用Finch的最新版本："com.github.finagle" %% "finch-core" % "0.15.1"和Scala 2.12

build.sbt文件：

name := "hello-finch"

version := "1.0"

scalaVersion := "2.12.2"

mainClass in (Compile, run) := Some("example.HelloWorld")

libraryDependencies ++= Seq(
  "com.github.finagle" %% "finch-core" % "0.15.1"
)

然后，src/main/scala/example/HelloWorld.scala文件：

package example

import io.finch._
import com.twitter.finagle.Http
import com.twitter.util.Await

object HelloWorld extends App {
  val api: Endpoint[String] = get("hello") { Ok("Hello, World!") }
  Await.ready(Http.server.serve(":8080", api.toServiceAs[Text.Plain]))
}

还要注意，拥有Await.ready()是强制性的-否则你的程序将立即退出。