My First Akka project in IntelliJ from scratch. Compile dependency error. - scala

Question

Every now and then I start things from scratch to make sure I know what all the intricate details of setting up a project are. I have a simple app like the following but I get some dependency issues that don't seem to point me anywhere. I'm using scala verions 2.11.
My SBT:
name := "Helios"
version := "1.0"
scalaVersion := "2.11.8"
resolvers += "Typesafe Repository" at "http://repo.typesafe.com/typesafe/releases/"
libraryDependencies ++= Seq(
"com.typesafe.akka" % "akka-actor" % "2.0.2",
"com.typesafe.akka" % "akka-slf4j" % "2.0.5")
My Sample Class
import com.echostar.ese.helios.core.Asset
import akka.actor._
class NSPSG extends Actor {
def receive = {
case a: Asset => {
println(s"NSPSG Received asset: ${a}")
}
case _ => println("Unexpected message received")
}
}
(Asset class is just a case class with id and title in it.)
Error Message:
C:\PROJECTS\active\Helios>sbt compile
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=256m; support was removed in 8.0
[info] Loading global plugins from C:\Users\dana.murad\.sbt\0.13\plugins
[info] Loading project definition from C:\PROJECTS\active\Helios\project
[info] Set current project to Helios (in build file:/C:/PROJECTS/active/Helios/)
[info] Updating {file:/C:/PROJECTS/active/Helios/}helios...
[info] Resolving jline#jline;2.12.1 ...
[info] Done updating.
[info] Compiling 3 Scala sources to C:\PROJECTS\active\Helios\target\scala-2.11\classes...
[error] missing or invalid dependency detected while loading class file 'package.class'.
[error] Could not access type ScalaObject in package scala,
[error] because it (or its dependencies) are missing. Check your build definition for
[error] missing or conflicting dependencies. (Re-run with `-Ylog-classpath` to see the problematic classpath.)
[error] A full rebuild may help if 'package.class' was compiled against an incompatible version of scala.
[error] missing or invalid dependency detected while loading class file 'Actor.class'.
[error] Could not access type ScalaObject in package scala,
[error] because it (or its dependencies) are missing. Check your build definition for
[error] missing or conflicting dependencies. (Re-run with `-Ylog-classpath` to see the problematic classpath.)
[error] A full rebuild may help if 'Actor.class' was compiled against an incompatible version of scala.
[error] C:\PROJECTS\active\Helios\src\main\scala\com\echostar\ese\helios\workers\NSPSG.scala:9: illegal inheritance;
[error] self-type com.echostar.ese.helios.workers.NSPSG does not conform to akka.actor.Actor's selftype akka.actor.Actor
[error] class NSPSG extends Actor {
[error] ^
[error] three errors found
[error] (compile:compileIncremental) Compilation failed
[error] Total time: 3 s, completed Apr 4, 2016 9:19:45 AM
My main App is just a println for now. It's not even calling this actor.
Am I using the wrong version of akka with scala 2.11? -Ylog-classpath didn't help

Answer 1

Don't know what fixed it but here's a list of things I did and the project compiles now.
Changed akka dependency line to this (added double percent and changed version back to 2.4)
libraryDependencies ++= Seq(
"com.typesafe.akka" %% "akka-actor" % "2.4.0"
)
Removed my Run configuration and added it back again. ( I think the path to main showed as red (invalid) so redoing it helped resolve it. I changed my package name and I don't think intelliJ picked up the rename well in build-conf)
Started another test project from IntelliJ menu (Akka Main in Scala) and that took a bit to download all dependencies. So maybe my project needed those and wasn't download them?
Removed commented out lines (got rid of a semi-colon). I don't think this did anything but full disclosure, technically I did touch the code even though my actor definition is exactly the same.