Kotlin Error 'unresolved reference' appears when trying to run Java Code from a Kotlin file
The code must be accessible for Kotlin. This means you have to compile (If you compile code in terminal: javac SampleFile.java The Base32Decoder.java file to generate the Base32Decoder.class.
Now generate the JAR-file with a link to the Kotlin file in command line:
jar cf app.jar Base32Decoder.class hello.kt

Now since you use kotlinc you can execute the code in command line like this:
kotlinc -classpath app.jar -script hello.kt

Now your code should run fine. The problem is that Kotlin didn't have access to the Base32Decoder.java class.

Referencing Problem when Java Class is used in Kotlin. There is the Java class Base32Decoder.java and code from this class is used in the Kotlin file hello.kt.
When I try to run Java code through a Kotlin file, an error occurs because of no reference could be established to the Java class Base32Decoder.
Error message:

hello.kt:4:25: error: unresolved reference: Base32Decoder

Base32Decoder Java class can't resolve the reference to it. Since this class is used inside the Kotlin file, the reference needs to work.
Code
fun main(args: Array<String>){
    val Base32Decoder = Base32Decoder()
   val rectangleArea: String = Base32Decoder.base32Decode("JBSWY3DPFQQFO33SNRSCC===")
   println("inside the Kotlin codes:" + rectangleArea)
}

How can I reference Java classes when I want to use Java code in Kotlin files?
