Exception in thread "main" java.lang.NoClassDefFoundError: org/rogach/scallop/ScallopConf

Question

As I want to execute the jar generated by my scala project in the Command Line Interface, I get the following problem: Exception in thread "main" java.lang.NoClassDefFoundError: org/rogach/scallop/ScallopConf

Although in the dependency file I mentionned scallop dependency as follow

import sbt._

object Dependencies {
  lazy val betterFiles = "com.github.pathikrit" %% "better-files" %  "3.7.0"
  lazy val scalaz = "org.scalaz" %% "scalaz-core" % "7.2.27"
  lazy val scallop = "org.rogach" %% "scallop" % "3.1.5"

  // -- Logging
  lazy val scalaLogging = "com.typesafe.scala-logging" %% "scala-logging" % "3.9.2"
  lazy val slf4jBackend = "org.slf4j" % "slf4j-simple" % "1.7.26"

  // -- Testing
  lazy val scalaTest = "org.scalatest" %% "scalatest" % "3.0.5"
}

My build.sbt file is the following:

import Dependencies._

ThisBuild / scalaVersion     := "2.12.5"
ThisBuild / sbtVersion       := "1.2.6"
ThisBuild / version          := "0.1.0-SNAPSHOT"

lazy val root = (project in file("."))
  .settings(
    name := "phenix-challenge",
    libraryDependencies ++= Seq(
      betterFiles,
      scalaz,
      scallop,

      scalaLogging,
      slf4jBackend % Runtime,

      scalaTest % Test
    )
  )

If you have an Idea that could resolve my Issue please HELP!

Many thanks in advance

Answer 1

To execute the jar generated by your scala project in the Command Line Interface you can use sbt plugin to assembly a fat-jar including your libraries/dependencies. Having such jar you would be able to run your app via java -jar ...

There are several SBT plugins for build a fat-jar. Perhaps the easiest one would be the sbt-assembly.

1. Add this plugin to file project/plugins.sbt (create this file if needed): addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.9")
2. Now use sbt to build a fat-jar:

sbt assembly

3. Then run via java -jar YouMainClass

Another option is to use pure sbt to run Main class using command sbt run , then you do really need to build a fat-jar.