HELP / FEATURE_REQUEST: Determining JsonSubType based on field at the same level

[ConnerDelahanty]

This is either a question, or a feature request if it does not exist!

Let's say I have a json object

{
   "field1" : "abc",
   "data": {
        "type": "TYPE1", 
        ...<TYPE1_SPECIFIC_DATA>
    }
}

This is relatively easy to do with Jackson with

public class Data<DataType extends AbstractDataType>
{
    public String field1;
    public DataType data;
}

JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type", visible = true)
@JsonSubTypes({
        @JsonSubTypes.Type(value = Type1Data.class, name = "TYPE1"),
})
public abstract class AbstractDataType
{
}

However, a lot of APIs will type the inner object based on a field in the out element, i.e. the JSON looks like

{
   "field1" : "abc",
   "type": "TYPE1", 
   "data": {
        ...<TYPE1_SPECIFIC_DATA>
    }
}

I cannot seem to find a way to have Jackson support this without writing my own deserializer? Am I missing something, or would this be a useful feature to add to it?

Thanks!

[cowtowncoder]

I'd need to google for details myself, but the trick is include = As.EXTERNAL_PROPERTY, f.ex see:

https://stacktobasics.com/jackson-sub-types

(instead of default include = As.PROPERTY)

So I hope this is enough breadcrumbs to locate the full information :)