Play Framework：如何使用嵌套元素将原始字段序列化为 JSON

Question

我需要序列化一个 String 和一个 Option[Boolean]:

val myWrites = (
  (__ \ "box").write(
    (
      (__ \ "name").write[String] ~
      (__ \ "default").writeNullable[Boolean]
    ).tupled
  )
)

如果 Option[Boolean] 是 Some 那么我希望

{
  "box": {
     "name": "John",
     "default": true
  }
}

... 而如果 Option[Boolean] 是 None 我希望

{
  "box": {
     "name": "John"
  }
}

给定以下变量...

val name = "John"
val default = Some(true)

...我如何将它们传递给 Writes？我试过这个：

myWrites.writes(name, defaul)

...但无法编译：

No Json serializer found for type play.api.libs.functional.FunctionalBuilder[play.api.libs.json.OWrites]#CanBuild2[String,Option[Boolean]].
Try to implement an implicit Writes or Format for this type.
[error] (__ \ "box").write(

Answer 1

我认为这只是你写的一个错字。你有默认与默认

我能够使用

import play.api.libs.json._
import play.api.libs.functional.syntax._

val myWrites = (
  (__ \ "box").write(
  (
   (__ \ "name").write[String] ~
     (__ \ "default").writeNullable[Boolean]
   ).tupled
)
 )

myWrites.writes("hi",Some(true))

我回来了

res0: play.api.libs.json.JsObject = {"box":{"name":"hi","default":true}}

Play Framework：如何使用嵌套元素将原始字段序列化为 JSON

Play Framework: How to serialize raw fields to JSON with nested elements

scala

playframework