Running spark scala example fails

Question

I'm new to both Spark and Scala. I've created an IntelliJ Scala project with SBT and added a few lines to build.sbt.

name := "test-one"

version := "1.0"

scalaVersion := "2.11.2"

libraryDependencies += "org.apache.spark" % "spark-core_2.10" % "1.1.0"

And I am facing this problem: 

Exception in thread "main" java.lang.NoClassDefFoundError: scala/collection/GenTraversableOnce$class
    at akka.util.Collections$EmptyImmutableSeq$.<init>(Collections.scala:15)
    at akka.util.Collections$EmptyImmutableSeq$.<clinit>(Collections.scala)
    at akka.japi.Util$.immutableSeq(JavaAPI.scala:209)
    at akka.actor.ActorSystem$Settings.<init>(ActorSystem.scala:150)
    at akka.actor.ActorSystemImpl.<init>(ActorSystem.scala:470)
    at akka.actor.ActorSystem$.apply(ActorSystem.scala:111)
    at akka.actor.ActorSystem$.apply(ActorSystem.scala:104)
    at org.apache.spark.util.AkkaUtils$.org$apache$spark$util$AkkaUtils$$doCreateActorSystem(AkkaUtils.scala:121)
    at org.apache.spark.util.AkkaUtils$$anonfun$1.apply(AkkaUtils.scala:54)
    at org.apache.spark.util.AkkaUtils$$anonfun$1.apply(AkkaUtils.scala:53)
    at org.apache.spark.util.Utils$$anonfun$startServiceOnPort$1.apply$mcVI$sp(Utils.scala:1446)
    at scala.collection.immutable.Range.foreach$mVc$sp(Range.scala:160)
    at org.apache.spark.util.Utils$.startServiceOnPort(Utils.scala:1442)
    at org.apache.spark.util.AkkaUtils$.createActorSystem(AkkaUtils.scala:56)
    at org.apache.spark.SparkEnv$.create(SparkEnv.scala:153)
    at org.apache.spark.SparkContext.<init>(SparkContext.scala:203)
    at TweeProcessor$.main(TweeProcessor.scala:10)
    at TweeProcessor.main(TweeProcessor.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: java.lang.ClassNotFoundException: scala.collection.GenTraversableOnce$class
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    ... 23 more

Answer 1

I think there is a version compatibility issue. Spark_core 2.10 is build using scala 2.10, and your sbt file mention you are using scala 2.11. 

Either:

downgrade the scala version to 2.10.4 as

name := "test-one"

version := "1.0"

//scalaVersion := "2.11.2"

scalaVersion := "2.10.4"

libraryDependencies += "org.apache.spark" % "spark-core_2.10" % "1.1.0"

Or:

upgrade your spark to 2.11