案例類自動對映

總的來說，使用 JSON 的最簡單方法是將案例類直接對映到 JSON（相同的欄位名稱，等效型別等）。

case class Person(
  name: String,
  age: Int,
  hobbies: Seq[String],
  pet: Pet
)

case class Pet(
  name: String,
  `type`: String
)

// these macros will define automatically the conversion to/from JSON
// based on the cases classes definition
implicit val petFormat = Json.format[Pet]
implicit val personFormat = Json.format[Person]

轉換為 Json

val person = Person(
  "Jsony McJsonface",
  18,
  Seq("Fishing", "Hunting", "Camping"),
  Pet("Doggy", "dog")
)

Json.toJson(person).toString
// {"name":"Jsony McJsonface","age":18,"hobbies":["Fishing","Hunting","Camping"],"pet":{"name":"Doggy","type":"dog"}}

從 Json 轉換

val str =
    """{
    |    "name" : "Jsony McJsonface",
    |    "age" : 18,
    |    "hobbies" : [ "Fishing", "Hunting", "Camping" ],
    |     "pet" : {
    |       "name" : "Doggy",
    |       "type" : "dog"
    |     }
    |}""".stripMargin

Json.parse(str).as[Person]
// Person(Jsony McJsonface,18,List(Fishing, Hunting, Camping),Pet(Doggy,dog))