Finch Hello World Error: Http not a member of com.twitter.finagle - scala

Question

I'm trying to use the scala finch library to build an API.
I have the following simple code:
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)
}
And a build.sbt file that looks like this:
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
)
When I compile and run the code I get this error message:
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
At this point I'm running out of ideas, it looks like a good library but it's a pain getting it working. Any help would be very much appreciated.

Answer 1

I have updated your example to work with the last version of Finch: "com.github.finagle" %% "finch-core" % "0.15.1" and also Scala 2.12
the build.sbt file:
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"
)
then, the src/main/scala/example/HelloWorld.scala file:
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]))
}
Notice also that having Await.ready() is mandatory - your program would exit right away otherwise.