CODEWITHSUNDEEP
scala
user6023600
user6023600

Reputation: 3

Scala main class error

My Program - HelloWorld.scala

object HelloWorld {
    def main(args: Array[String]): Unit = {
        println("Hello, world!")
    }
}

jar cvfe HelloWorld.jar HelloWorld HelloWorld*.class

After jar file is created i tried to get the output from jar file

java -jar HelloWorld.jar

but i got the error

    Exception in thread "main" java.lang.NoClassDefFoundError: scala/Predef$
        at HelloWorld$.main(HelloWorld.scala:12)
        at HelloWorld.main(HelloWorld.scala)
Caused by: java.lang.ClassNotFoundException: scala.Predef$
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source)
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(Unknown Source)
        at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
        ... 2 more

Upvotes: 0

Views: 907

Answers (2)

Dmytro Mitin
Dmytro Mitin

Reputation: 51658

Add line 

Class-Path: /home/dmitin/.m2/repository/org/scala-lang/scala-library/2.1‌​2.3/scala-library-2.‌​12.3.jar

(i.e. your location of scala-library) to HelloWorld.jar/META-INF/MANIFEST.MF.

Then 

java -jar HelloWorld.jar Dmytro

produces 

Hello, Dmytro!

Upvotes: 0

gtosto
gtosto

Reputation: 1341

You have to include the scala runtime and libraries into the java classpath, you can certainly do that from commandline, but I suggest you to use more comfortable tools, see for example the tutorial at www.scala-lang.org

Upvotes: 1

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