英文:
Sttp, Circe, Json - how to deserialize Json to custom object?
问题
我有一个简单的案例类，用于模拟Http响应：
case class Other(name: String, age: Int)
case class MyResponse(id: String, name: String, others: List[Other])
我为它们创建了解码器：
implicit val decoderOther: Decoder[Other] = deriveDecoder[Other]
implicit val decoderMyResponse: Decoder[MyResponse] = deriveDecoder[MyResponse]
但是当我在sttp http客户端上调用它时：
basicRequest.(...).get(...).response(asJson[MyResponse].getRight).send(backend).map(_)
我遇到了一个Desarialization错误：
sttp.client3.DeserializationException: DecodingFailure at .id Missing required field
我不知道为什么它无法被正确解析。解码器看起来没问题。当我将MyResponse更改为circe的Json类时，它可以正常工作：
Response([{ "id": "121", "name": "test", "others": [] }])
但我想将其解析为我的模型。你能帮助我吗？
英文:
I have a simple case class which models Http response:
case class Other(name: String, age: Int)
case class MyResponse(id: String, name: String, others: List[Other])
I created decoders for them:
implicit val decoderOther: Decoder[Other] = deriveDecoder[Other]
implicit val decoderMyResponse: Decoder[MyResponse] = deriveDecoder[MyResponse]
But when I call it on sttp http client:
basicRequest.(...).get(...).response(asJson[MyResponse].getRight).send(backend).map(_)
I got a Desarialization error:
sttp.client3.DeserializationException: DecodingFailure at .id Missing required field
I don't know why it cannot be parsed correctly. Decoders seems fine. When I change MyResponse to circe Json class it works fine:
Response([{ "id": "121", "name": "test", "others": [] }])
but I would like to parse it to my model. Can you help me?
答案1
得分: 2
如果您编写asJson[MyResponse]，则需要使用Encoder而不是Decoder。
因此，请添加以下内容：
implicit val encoderOther: Encoder[Other] = deriveEncoder[Other]
implicit val encoderMyResponse: Encoder[MyResponse] = deriveEncoder[MyResponse]
您可以将Encoder和Decoder替换为Codec：
implicit val codecOther: Codec[Other] = deriveCodec[Other]
implicit val codecMyResponse: Codec[MyResponse] = deriveCodec[MyResponse]
MyResponse("121", "test", List()).asJson.noSpaces
// {"id":"121","name":"test","others":[]}
如果您仍然遇到问题，请准备一个MCVE。
英文:
If you write asJson[MyResponse] you need Encoder rather than Decoder.
So add
implicit val encoderOther: Encoder[Other] = deriveEncoder[Other]
implicit val encoderMyResponse: Encoder[MyResponse] = deriveEncoder[MyResponse]
You can replace Encoder and Decoder with Codec
implicit val codecOther: Codec[Other] = deriveCodec[Other]
implicit val codecMyResponse: Codec[MyResponse] = deriveCodec[MyResponse]
MyResponse("121", "test", List()).asJson.noSpaces
// {"id":"121","name":"test","others":[]}
https://scastie.scala-lang.org/DmytroMitin/W3wgn0gbRXyA1vRI6OyoUg/1
If you still experience issues please prepare MCVE.
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