Object serialization example in Scala

Deserialization.scala

import java.io._

@SerialVersionUID(15L)
class Animal(name: String, age: Int) extends Serializable {
  override def toString = s"Animal($name, $age)"
}

case class Person(name: String)

// or fork := true in sbt
class ObjectInputStreamWithCustomClassLoader(
  fileInputStream: FileInputStream
) extends ObjectInputStream(fileInputStream) {
  override def resolveClass(desc: java.io.ObjectStreamClass): Class[_] = {
    try { Class.forName(desc.getName, false, getClass.getClassLoader) }
    catch { case ex: ClassNotFoundException => super.resolveClass(desc) }
  }
}

object MyDeserialize extends App {
  val fis = new FileInputStream("../a.tmp")
  val ois = new ObjectInputStreamWithCustomClassLoader(fis)

  val animal = ois.readObject
  val person = ois.readObject
  ois.close
  println(animal)
  println(person)
}

Serialization.scala

import java.io.FileOutputStream
import java.io.ObjectOutputStream

@SerialVersionUID(15L)
class Animal(name: String, age: Int) extends Serializable {
  override def toString = s"Animal($name, $age)"
}

case class Person(name: String) extends Serializable

object MySerialize extends App {
  val fos = new FileOutputStream("../a.tmp")
  val oos = new ObjectOutputStream(fos)

  oos.writeObject(new Animal("Dvorak", 12))
  oos.writeObject(Person("Dijkstra"))
  oos.close
}

Awesome, this worked perfectly for me!

Thank you very much:smiley:! I have tried several other approaches (libraries like Scala Pickling, uPickle, Sphere JSON, Kryo + Chill), but none was able to properly handle dynamic (de)serialization and/or stuff like List filled with case classes or generic container classes.

Thank you very much!

Awesome, this worked perfectly for me!

+1 Bravo

@ramn This worked like a charm. I tried all other suggestions like pointing the jar via "spark.jars" but it didn't work. Did anyone ever figure out why we need this?