Kryo serialization works out-of-the-box with Kotlin

kryo.kt

package org.cakesolutions.spark.kryo

import com.esotericsoftware.kryo.Kryo
import com.esotericsoftware.kryo.io.Input
import com.esotericsoftware.kryo.io.Output
import java.io.FileInputStream
import java.io.FileOutputStream

fun main(args: Array<String>) {
    val kryo = Kryo()

    val output = Output(FileOutputStream("file.bin"))
    val user = User("Mario", Address("Manchester", "Flat 86", "M###XX"))
    kryo.writeObject(output, user)
    output.close()

    val input = Input(FileInputStream("file.bin"))
    val u = kryo.readObject(input, javaClass<User>())
    input.close()
    println("u = ${u}")
}

data class Address(val city: String? = null, val line: String? = null, val postCode: String? = null)

data class User(val name: String? = null,
                val address: Address? = null)