Are jar files built in sbt portable?

Question

I had to build a jar from my scala code using sbt:

sudo sbt package

It used my build file:

name := "PSG CCD"
version := "1.0"
scalaVersion := "2.11.8"

resolvers += "Spark Packages Repo" at "http://dl.bintray.com/spark-packages/maven"

libraryDependencies ++= Seq(
        "org.apache.spark" %% "spark-core" % "2.2.0",
        "org.apache.spark" %% "spark-sql" % "2.2.0",
        "org.apache.spark" %% "spark-streaming" % "2.2.0",
        "neo4j-contrib" % "neo4j-spark-connector" % "2.0.0-M2"
)

I also built the jar just fine. Then, I transfer it via FTP to my spark server and do a spark-submit:

 spark-submit --class "PSGApp" --master local[4] psg_ccd.jar 

I get this error:

Exception in thread "main" java.lang.NoClassDefFoundError: org/neo4j/spark/Neo4j
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
    at java.lang.Class.getMethod0(Class.java:3018)
    at java.lang.Class.getMethod(Class.java:1784)
    at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:739)
    at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:180)
    at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:205)
    at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:119)
    at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)
Caused by: java.lang.ClassNotFoundException: org.neo4j.spark.Neo4j
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    [truncated, 10 more messages]

So even though I have the neo4j-spark-connector in the dependency file, it doesn't seem to find it when I run it through spark. Now this spark is ran on a different machine than I built the jar from scala on. Does this matter? Is there a folder of libs I need to copy and drop somewhere?

I am guessing the library information of the neo4j spark connection dependency was not built into the jar I am trying to run.

Maybe I am missing a switch to force that?

Answer 1

You need use sbt assembly plugin to generate a fat jar with dependencies. There are many examples in Stackoverflow. I show you one: How to build an Uber JAR (Fat JAR) using SBT within IntelliJ IDEA?