Type Serialization

This page covers serialization of Scala-specific JVM types in native mode. For cross-language Scala models, use the xlang path described in Schema IDL And Xlang.

When compatible mode is enabled, Scala readers use the JVM compatible-read rules for selected scalar field type changes. A matched field can read between Boolean, String, numeric scalars, and java.math.BigDecimal when the converted value has the same logical value. For example, "true" and "false" can be read as booleans, "123" can be read as a numeric field that can hold 123, numbers and decimals can be read as canonical strings, and numeric widening or narrowing succeeds only when no precision or range is lost. Numeric strings use finite ASCII decimal syntax. Invalid strings and lossy conversions fail during deserialization. Optional and boxed fields still compose with these conversions, but reference-tracked scalar type changes are incompatible.

Setup

All examples assume the following setup:

import org.apache.fory.Fory
import org.apache.fory.scala.ForyScala

val fory = ForyScala.builder().withXlang(false)
  .build()

Case Class

case class Person(github: String, age: Int, id: Long)

fory.register(classOf[Person])

val p = Person("https://github.com/chaokunyang", 18, 1)
println(fory.deserialize(fory.serialize(p)))

POJO Class

class Foo(f1: Int, f2: String) {
  override def toString: String = s"Foo($f1, $f2)"
}

fory.register(classOf[Foo])

println(fory.deserialize(fory.serialize(new Foo(1, "chaokunyang"))))

Object Singleton

Scala object singletons are serialized and deserialized to the same instance:

object MySingleton {
  val value = 42
}

fory.register(MySingleton.getClass)

val o1 = fory.deserialize(fory.serialize(MySingleton))
val o2 = fory.deserialize(fory.serialize(MySingleton))
println(o1 == o2) // true

Collection

Scala collections are fully supported:

val seq = Seq(1, 2)
val list = List("a", "b")
val map = Map("a" -> 1, "b" -> 2)

println(fory.deserialize(fory.serialize(seq)))
println(fory.deserialize(fory.serialize(list)))
println(fory.deserialize(fory.serialize(map)))

Tuple

All Scala tuple types (Tuple1 through Tuple22) are supported:

val tuple2 = (100, 10000L)
println(fory.deserialize(fory.serialize(tuple2)))

val tuple4 = (100, 10000L, 10000L, "str")
println(fory.deserialize(fory.serialize(tuple4)))

Enum

Scala 3 Enum

enum Color { case Red, Green, Blue }

fory.register(classOf[Color])

println(fory.deserialize(fory.serialize(Color.Green)))

Scala 2 Enumeration

object ColorEnum extends Enumeration {
  type ColorEnum = Value
  val Red, Green, Blue = Value
}

fory.register(Class.forName("scala.Enumeration.Val"))

println(fory.deserialize(fory.serialize(ColorEnum.Green)))

Note: For Scala 2 Enumeration, you may need to register scala.Enumeration.Val or enable reference tracking to avoid StackOverflowError.

Option

val some: Option[Long] = Some(100)
println(fory.deserialize(fory.serialize(some)))

val none: Option[Long] = None
println(fory.deserialize(fory.serialize(none)))

Either

val right: Either[String, Int] = Right(42)
println(fory.deserialize(fory.serialize(right)))

val left: Either[String, Int] = Left("error")
println(fory.deserialize(fory.serialize(left)))

Nested Types

Complex nested structures are fully supported:

case class Address(street: String, city: String)
case class Company(name: String, address: Address)
case class Employee(name: String, company: Company, tags: List[String])

fory.register(classOf[Address])
fory.register(classOf[Company])
fory.register(classOf[Employee])

val employee = Employee(
  "John",
  Company("Acme", Address("123 Main St", "Springfield")),
  List("developer", "scala")
)

println(fory.deserialize(fory.serialize(employee)))