hello! not specific to Kotlin but was wondering if...

# jackson-kotlin

[Dariusz Kuc]

hello! not specific to Kotlin but was wondering if anyone here knows what is the equivalent of @JsonValue for deserialization - e.g. I need to create wrapper around String value

data class Example(@JsonValue val value: String)

above gets correctly serialized to just that actual value . Wondering if there is some handy annotation to deserialize it back without writing custom deserializer - or custom deserializer is the only way?

[araqnid]

I thought if the constructor had just a single String parameter, Jackson would automatically deserialize it by constructing on the string - maybe the Kotlin module prevents that and enforces data objects should be JSON objects?

[araqnid]

hm, yes, including the Kotlin module does prevent it from just working sadface

[araqnid]

You can do this though, to which is at least a bit less painful that implementing a full custom deserializer:

@JsonDeserialize(converter = Example.Converter::class)
    data class Example(@JsonValue val whatever: String) {
        class Converter : StdConverter<String, Example>() {
            override fun convert(value: String) = Example(value)
        }
    }

[Jukka Siivonen]

data class Value @JsonCreator constructor (@get:JsonValue val value: String)

maybe?

[araqnid]

unfortunately not. Ah, but making a JsonCreator method as a static method works:

data class Example(@JsonValue val whatever: String) {
        companion object {
            @JvmStatic
            @JsonCreator
            fun create(str: String) = Example(whatever = str)
        }
    }

[araqnid]

I thought I tried this before, I might have missed the @JvmStatic annotation

[Dariusz Kuc]

cool, thanks for the help! let me try it out

[Dariusz Kuc]

finally got a chance to test it

[Dariusz Kuc]

works like a charm

[Dariusz Kuc]

thanks!