如果class在scala 3.2.2中失败,但在2.13.8中成功,则使用默认值进行ZIO-JSON解码

atmip9wb  于 6个月前  发布在  Scala
关注(0)|答案(1)|浏览(68)

我有一个简短的测试程序,它无法解码jsonstring,因为jsonstring中缺少personId。
但是,我在case类中根据zio文档为personId设置了一个默认值
https://zio.dev/zio-json/decoding#automatic-derivation-and-case-class-default-field-values
我做错什么了?

import zio.*
import zio.json.*
import zio.schema.{DeriveSchema, Schema}

final case class Person(personId: Long = 1, name: String, age: Int)

object Person {
  implicit val decoder: JsonDecoder[Person] = DeriveJsonDecoder.gen[Person]
}

object MyApp extends ZIOAppDefault {

  override def run: ZIO[Environment with ZIOAppArgs, Any, Any] =
    for {
      _ <- Console.printLine("Decoding a JSON string representing a person...")
      jsonString =
        """
        {
           "name": "John",
           "age": 30
        }
        """.stripMargin
      result <- ZIO.fromEither(jsonString.fromJson[Person])
      _ <- Console.printLine(s"Decoded Person: $result")
    } yield ExitCode.success
}

字符串

输出

Decoding a JSON string representing a person...
timestamp=2023-11-02T21:11:01.198368Z level=ERROR thread=#zio-fiber-1 message="" cause="Exception in thread "zio-fiber-4" java.lang.String: .personId(missing)
    at <empty>.MyApp.run(MyApp2.scala:25)
    at <empty>.MyApp.run(MyApp2.scala:27)"

Process finished with exit code 1

版本:

val zioVersion            = "2.0.13"
val zioJsonVersion        = "0.5.0"

scala version 3.2.2

cuxqih21

cuxqih211#

我能够解决这个问题的基础上,我从discord社区得到的帮助。有一个类似的问题报告在https://github.com/zio/zio-json/issues/779

解决方法是设置scala编译器选项

  • Yretain树

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