Jackson Databind @JsonAnySetter and @JsonUnwrapped deserialize property twice

I did such test.

First define a pojo:

import com.fasterxml.jackson.annotation.JsonAnyGetter;
import com.fasterxml.jackson.annotation.JsonAnySetter;
import com.fasterxml.jackson.annotation.JsonUnwrapped;
import lombok.Data;

import java.util.HashMap;
import java.util.Map;

@Data
public class ESModel {

    private Long id;

    @JsonUnwrapped
    private Result result;

    private Map<String, Object> extra = new HashMap<>();

    @JsonAnyGetter
    public Map<String, Object> getExtra() {
        return extra;
    }

    @JsonAnySetter
    public void set(String key, Object value) {
        extra.put(key, value);
    }

    @Data
    public static class Result {
        private String name;
    }
}

Then test serialization:

    @Test
    public void test001() {
        ESModel esModel = new ESModel();
        ESModel.Result child = new ESModel.Result();
        child.setName("aaa");
        Map<String, Object> map = new HashMap<>();
        map.put("age", 12);

        esModel.setId(1L);
        esModel.setResult(child);
        esModel.setExtra(map);
        System.out.println(JSON.toJSONString(esModel));
    }

The output is following which I expected.

{"id":1,"name":"aaa","age":12}

And then test deserialization:

        String json = "{\"id\":1,\"name\":\"aaa\",\"age\":12}";
        ESModel model = JSON.parseObject(json, ESModel.class);
        System.out.println(model);

The output is following which out of my expectation. The property 'name' has been deserialized twice.

ESModel(id=1, result=ESModel.Result(name=aaa), extra={name=aaa, age=12})

PS：The JSON utitliy class is follow:

public abstract class JSON {

    private static ObjectMapper objectMapper;

    static {
        objectMapper = new ObjectMapper();
        objectMapper.setTimeZone(TimeZone.getDefault());
        objectMapper.setSerializationInclusion(NON_ABSENT);
        objectMapper.disable(FAIL_ON_UNKNOWN_PROPERTIES);
        objectMapper.disable(READ_DATE_TIMESTAMPS_AS_NANOSECONDS);
        objectMapper.disable(WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS);
        objectMapper.disable(DEFAULT_VIEW_INCLUSION);
        objectMapper.enable(ALLOW_BACKSLASH_ESCAPING_ANY_CHARACTER);
        objectMapper.enable(PROPAGATE_TRANSIENT_MARKER);
    }

    /*-----------------------deserialization-----------------------*/

    public static <T> T parseObject(String json, Class<T> clazz) {
        try {
            return objectMapper.readValue(json, clazz);
        } catch (IOException e) {
            throw new JSONException(e.getMessage(), e);
        }
    }

    /*-----------------------serialization-----------------------*/

    public static String toJSONString(Object object) {
        try {
            return objectMapper.writeValueAsString(object);
        } catch (IOException e) {
            throw new JSONException(e.getMessage(), e);
        }
    }
}

Comment From: cowtowncoder

Unfortunately the way unwrapped handling is implemented there is no way for parent deserializer to know which properties it has might be handled by child deserializers, and as a result, any-setter will be given anything not consumed by deserializer itself.

With 3.0 handling can be changed and hope is this could be resolved then.

Comment From: Bijnagte

I just ran into a different flavor of this bug involving record classes which completely fail to deserialize when both annotations are present. Order of properties does not matter. Example code:

    record NameId(String id, String name) {}
    @JsonInclude(JsonInclude.Include.NON_NULL)
    record Nested(
        @JsonUnwrapped NameId nameId,
        @JsonAnySetter @JsonAnyGetter Map<String, Object> additionalProperties) {}

    String json =
      """
      { "id": "12345",
        "name": "Test",
        "otherProperty": "value"
      }
      """;

    ObjectMapper objectMapper = new ObjectMapper();
    Nested nested = objectMapper.readValue(json, Nested.class); 

throws an exception like:

java.lang.ClassCastException: Cannot construct instance of `Nested`, problem: Nested cannot be cast to class java.util.Map

Comment From: JooHyukKim

@Bijnagte Did your case Worked before, then stopped working? If so, could you provide which version behavior changed?

And have you tried the latest version out there? 2.19 or 2.20