What's the Jackson deserialization equivalent of @JsonUnwrapped?

Question

Say I have the following class:

public class Parent {
  public int age;
  @JsonUnwrapped
  public Name name;
}

Producing JSON:

Answer 1

You can use @JsonCreator with @JsonProperty for each field:

@JsonCreator
public Parent(@JsonProperty("age") Integer age, @JsonProperty("firstName") String firstName,
        @JsonProperty("lastName") String lastName) {
    this.age = age;
    this.name = new Name(firstName, lastName);
}

Jackson does type checking and unknown field checking for you in this case.

Answer 2

@JsonUnwrapped works for both serialization and deserialization, you shouldn't need to take any additional steps.

Answer 3

It does work for deserialization as well, although it's not mentioned in the docs explicitly, like you said. See the unit test for deserialization of @JsonUnwrapped here for confirmation - https://github.com/FasterXML/jackson-databind/blob/d2c083a6220f2875c97c29f4823d9818972511dc/src/test/java/com/fasterxml/jackson/databind/struct/TestUnwrapped.java#L138

Answer 4

For those who googled here like me, trying to resolve issue when deserializing unwrapepd Map, there is a solution with @JsonAnySetter:

public class CountryList
{

    Map<String, Country> countries = new HashMap<>();

    @JsonAnySetter
    public void setCountry(String key, Country value)
    {
        countries.put(key, value);
    }

}