@Target(value={ANNOTATION_TYPE,FIELD,METHOD,PARAMETER})
@Retention(value=RUNTIME)
public @interface JsonUnwrapped

Annotation used to indicate that a property should be serialized "unwrapped"; that is, if it would be serialized as JSON Object, its properties are instead included as properties of its containing Object. For example, consider case of POJO like:

  public class Parent {
    public int age;
    public Name name;
  }
  public class Name {
    public String first, last;
  }

which would normally be serialized as follows (assuming @JsonUnwrapped had no effect):

  {
    "age" : 18,
    "name" : {
      "first" : "Joey",
      "last" : "Sixpack"
    }
  }

can be changed to this:

  {
    "age" : 18,
    "first" : "Joey",
    "last" : "Sixpack"
  }

by changing Parent class to:

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

Annotation can only be added to properties, and not classes, as it is contextual.

Also note that annotation only applies if

• Value is serialized as JSON Object (can not unwrap JSON arrays using this mechanism)
• Serialization is done using BeanSerializer, not a custom serializer
• No type information is added; if type information needs to be added, structure can not be altered regardless of inclusion strategy; so annotation is basically ignored.