@JsonValue annotation in Kotlin's enum class' value property

Question

I'm unable to apply the Jackson's @JsonValue annotation on the value parameter of enum class:

enum class CancellationReason(@JsonValue val code: String) {
    CUSTOMER_RESIGNED("20"),
    ERRORS_IN_FOO("21"),
    ERRORS_IN_BAR("24");
}

The error message states: This annotation in not applicable to target 'value parameter'. What's the problem?

Answer 1

You can upgrade jackson-module-kotlin to version 2.9.0, and the error will be gone, because the @JsonValue annotation gets a target FIELD in that version.

Alternatively, fix that by specifying the annotation use-site target by adding @get::

enum class CancellationReason(@get:JsonValue val code: String) {
    CUSTOMER_RESIGNED("20"),
    ERRORS_IN_FOO("21"),
    ERRORS_IN_BAR("24");
}