[Resolved] hi, guys i have some trouble during wor...

# announcements

[Vasily Scherbakov]

[Resolved]
hi, guys
i have some trouble during working with jakson. i wrote next class

class NeuralNetworkModelingModuleInput (
    @JsonProperty("module")
    val ModuleName: String = "neural_network_modeling",
...
)

I expects that field ModuleName would be mapped to "module" field of json. And for deserialization its work correct, but when i try to serialize this class, i get json with field "moduleName". Seems like object mapper simply ignore JsonProperty annotation. Also this may ocurred cause of for deserialization i use mapper in ktor server, and standalone mapper for serialization:

private fun<T> serialize(obj: T): String {
        return mapper
            .configure(SerializationFeature.INDENT_OUTPUT, true)
            .writeValueAsString(obj)
    }

Can anyone please help me?

[Vasily Scherbakov]

solve this issue by adding

@JsonAutoDetect(fieldVisibility = JsonAutoDetect.Visibility.ANY)

this annotation to my class. but now occured another problem: all fields was duplicated after serialization. For example, for fied ModuleName with JsonName module after serialization exist both fields: module and ModuleName

[Vasily Scherbakov]

"module" : "neural_network_modeling",
"moduleName" : "neural_network_modeling"

[Umar Ata]

You may try to rename the moduleName to module in your class

[Vasily Scherbakov]

ok, thats would work. but for another field(for example nEpoch) didnt. nEpoch serialized as nepoch, but i expected n_epoch

[Umar Ata]

https://www.baeldung.com/kotlin/jackson-kotlin

[Umar Ata]

It has one working example

[Vasily Scherbakov]

ooo, thanks!

[Vasily Scherbakov]

Unfortunately method described in this article didn't help me 🤔

[Dave K]

Instead of @JsonProperty try changing to @get:JsonProperty

[Dave K]

Does your mapper have the kotlin module registered?

[Vasily Scherbakov]

Yes, it registered

[Vasily Scherbakov]

@Dave K Thanks a lot! That helps me. Reason of this unexpected behaviour was that i use annotations in constructor instead of standard fields