CODEWITHSUNDEEP
jsonspringspring-bootkotlin
inconnu
inconnu

Reputation: 769

objectmapper.readValue() fails with error "no String-argument constructor/factory method to deserialize from String value"

My objectmapper.readValue() function throws an error that says "Cannot construct instance of MyErrorMessage (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value."

What's wrong with my MyErrorMessage class that makes objectmapper fail?

This is the JSON I'm trying to parse.

{
  "meta": {
    "id": "43225a4853b5497a",
    "time": "2020-06-03T13:36:03.391814Z"
  },
  "datadetail": {
    "aKey": "hweriu-erw",
    "aTypes": [
      {
        "bKey": "ewrf-7e9f",
        "cKey": "12ddf3",
        "status": "ERROR",
        "errorMessage": {
          "message": "Not found"
        }
      }
    ],
    "status": "ONE",
    "errorMessage": "ERROR with aKey"
  }
}

This is the function and the classes.

private fun ParseResponse(responseMessage: String): MyResponse{
    try {
        val objectMapper = ObjectMapper()
        return objectmapper.readValue(message, MyResponse::class.java)
    }catch (e: JsonProcessingException) {
      throw IllegalArgumentException("json was invalid $responseMessage", e)
    }
}

data class MyResponse(
    val meta: Metainfo,
    val datadetail: DataResponse
)

data class MetaInfo(
    val id: String,
    val time: Instant
)

data class DataResponse(
    val aKey: MyKey,
    val aTypes: List<TypesResponse>,

    val aNumber: String? = null,
    val status: StatusType,
    val errorMessage: MyErrorMessage = null
)

enum class StatusType{
    OK,
    ERROR
}

data class TypesResponse(
    val bKey: MyBKey,
    val cKey: MyCKey,
    val status: StatusType,
    val errMessage: MyErrorMessage? = null
)

data class MyErrorMessage(
    @JsonProperty("message")
    val message: String,

    @JsonProperty("context")
    val context: MyContext?,
){
    constructor(message: String) : this(
        message = message,
        context = null
    )

    enum class MyContext{
        ONE, TWO, THREE
    }
}

Upvotes: 0

Views: 1593

Answers (1)

Jo&#227;o Dias
Jo&#227;o Dias

Reputation: 17510

Your JSON does not follow your class structure. You have "errorMessage": "ERROR with aKey", but your errorMessage in DataResponse is in fact a MyErrorMessage which is an object, not a simple String.

It would need to be:

"errorMessage": {
  "message": "ERROR with aKey"
}

If that is not an option, then you need a custom Jackson JSON Deserializer for your MyErrorMessage that can handle that. You can check an example here.

Upvotes: 2

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