使用 Jackson 和不同类型的 object 反序列化 JSON

Question

I am trying to deserialize this payload:

{
   "commonField": {"a": "1234"},
   "X": {"c": "1234", "d": "5678"}
}

but "X" could be "Y" with a different definition.

My idea is having a DTO with the commonField and an Interface to be implemented by "X" or "Y".

I have been trying with JsonSubTypes but didn't work ( snippet ) Any idea?

Answer 1

try this:

JSON.parse(JSON.stringify({
  "commonField": {"a": "1234"},
  "X": {"c": "1234", "d": "5678"}
}))

Answer 2

I'd probably deserialize to:

public class Payload {
    public CommonType commonField;
    public X x;
    public Y y;
}

Fields not present in the JSON will remain null .

Edit

a single field with polymorphic content

You can achieve this with a few setters:

public class Payload {
    public CommonType commonField;
    private TheInterface polyField;

    public TheInterface getPolyField() {
        return polyField;
    }

    public void setX(X x) {
        polyfield = x;
    }

    public void setY(Y y) {
        polyfield = y;
    }
}

assuming that X and Y are declared to implement TheInterface .