@JsonCreator ignored when deserializing map keys

I’m unsure whether this is a bug or expected behavior, but I found it a bit surprising. Given the following class:

class Key {

    private final String value;

    private Key(final String value) {
        this.value = value;
    }

    @JsonCreator(mode = JsonCreator.Mode.DELEGATING)
    public static Key of(final String value) {
        return new Key(value);
    }
}

Then, when a Key value is deserialized, the factory method annotated with @JsonCreator is called as expected. If Key is used as a key in a Map though, the factory method is not called and Key’s private constructor is used directly instead.

Key is of course reduced to demonstrate the issue and hence lacking all properties that would make it actually useful as a key in a map.

I tried the above with version 2.9.7. A repository demonstrating the issue can be found at https://github.com/Trundle/jackson-databind-oddity

[cowtowncoder]

I think this was solved along with #3143 – test now passes. Fix will be included in 2.13.0 (since it required bigger refactoring of things unfortunately, cannot safely backport).

[cowtowncoder]

@Stephan202 that’ll be awesome, whenever – I probably won’t have time to look into this particular issue immediately anyway. But will be good to have reproduction.