Spray-json deserializing nested object

Question

How to deserialize nested objects correctly in spray-json?

    import spray.json._

    case class Person(name: String)

    case class Color(n: String, r: I         


        

Answer 1

The example below demonstrates JSON -> Abstract Syntax Tree -> Scala Case Classes and back with custom field names and support for optional case class members. The example is derived from the spray-json documentation at https://github.com/spray/spray-json for version 1.2.5.

package rando

import spray.json._

case class Color(name: String, red: Int, green: Int, blue: Int)

case class Team(name: String, color: Option[Color])

object MyJsonProtocol extends DefaultJsonProtocol {
  implicit val colorFormat = jsonFormat(Color, "name", "r", "g", "b")
  implicit val teamFormat = jsonFormat(Team, "name", "jersey")
}
import MyJsonProtocol._

object GoSox extends App {
  val obj = Team("Red Sox", Some(Color("Red", 255, 0, 0)))
  val ast = obj.toJson
  println(obj)
  println(ast.prettyPrint)
  println(ast.convertTo[Team])
  println("""{ "name": "Red Sox", "jersey": null }""".asJson.convertTo[Team])
  println("""{ "name": "Red Sox" }""".asJson.convertTo[Team])
}

The example outputs the following when executed:

Team(Red Sox,Some(Color(Red,255,0,0)))
{
  "name": "Red Sox",
  "jersey": {
    "name": "Red",
    "r": 255,
    "g": 0,
    "b": 0
  }
}
Team(Red Sox,Some(Color(Red,255,0,0)))
Team(Red Sox,None)
Team(Red Sox,None)