SerdeTest.scala

package serde

import java.io.{ByteArrayInputStream, ByteArrayOutputStream, ObjectInputStream, ObjectOutputStream}

sealed trait Color
case object RED extends Color
case class A(colors:Seq[Color])

object SerdeTest {

  def serialize(a: A): Array[Byte] = {
    val b  = new ByteArrayOutputStream()
    val oo = new ObjectOutputStream(b)
    oo.writeObject(a)
    oo.close()
    b.toByteArray
  }

  def deserialize(b: Array[Byte]): Any = {
    val in  = new ByteArrayInputStream(b)
    val oi  = new ObjectInputStream(in)
    val obj = oi.readObject()
    obj
  }

  def main(args:Array[String]): Unit = {
    val a = A(Seq(RED))
    val b = serialize(a)      // OK
    val a1 = deserialize(b)   // NG: cannot assign instance of scala.collection.generic.DefaultSerializationProxy to field serde.A.colors of type scala.collection.immutable.Seq in \
instance of serde.A
    println(a1)
  }

}