Jackson deserialize object or array

Question

I have a Jackson Question.

Is there a way to deserialize a property that may have two types, for some objects it appears like this

\"someObj\" : { \"         


        

Answer 1

None of the other answers worked for me:

• We can't use a modifier since the ObjectMapper cannot be modified and we use a @JsonDeserialize annotation to install the deserializer.
• We don't have access to the ObjectMapper either.
• We need the resulting Map to be properly typed, which didn't seem to work with ObjectCodec.treeToValue.

This is the solution that finally worked:

public class EmptyArrayToEmptyMapDeserializer extends JsonDeserializer> {
    @Override
    public Map deserialize(JsonParser parser,
            DeserializationContext context) throws IOException {
        if (parser.getCurrentToken() == JsonToken.START_ARRAY) {
            // Not sure what the parser does with the following END_ARRAY token, probably ignores it somehow.
            return Map.of();
        }
        return context.readValue(parser, TypeFactory.defaultInstance().constructMapType(Map.class, String.class, SomeComplexType.class));
    }
}