播放Framework Scala格式的大JSON(未找到unapply或unapplySeq函数) [英] Play Framework Scala format large JSON (No unapply or unapplySeq function found)

问题描述

我需要在服务器上接收到一个大型JSON(超过22个字段). 我有一个包含很多字段的案例类:

I need to receive a big JSON on my server (more than 22 fields). I have a case class with a lot of fields:

case class Filters(objectType: Option[String] = None,
     deal: Option[String] = None,
     roomsCount: Option[String] = None,
     region: Option[Int] = None,
     district: Option[Int] = None,
     direction: Option[Int] = None
     ...
)

并且JSON格式在控制器中起作用:

And JSON format function in controller:

implicit val filtersFormat = Json.format[Filters]

编译时出现错误:

[error] WebSockets.scala:18: No unapply or unapplySeq function found
[error]   implicit val filtersFormat = Json.format[Filters]
[error]                                          ^

有没有一种方法可以解决此问题而又不将JSON分成小部分?

Is there a way to solve the problem without breaking JSON to small parts?

推荐答案

我是这样做的:

case class Filters(part1: Part1, part2: Part2, ...)

case class Part1(
    field1: Field1,
    field2: Field2,
    ...
    field10: Field10,
)

object Part1 {
    implicit val part1Format = Json.format[Part1]
}

...

object Filters {
    implicit val filtersReads = (
        JsPath.read[Part1] and
        JsPath.read[Part2] and
        ...
    )(Filters.apply _)

    implicit val filtersWrites = (
        JsPath.write[Part1] and
        JsPath.write[Part2] and
        ...
    )(unlift(Filters.unapply))
}

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