Package com.fasterxml.jackson.annotation

Annotation Type JsonUnwrapped

@Target({ANNOTATION_TYPE,FIELD,METHOD,PARAMETER})
@Retention(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 -- and deserialized reproducing "missing" structure. 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. When values are deserialized "wrapping" is applied so that serialized output can be read back in.

Also note that annotation only applies if:

• Value is serialized as an Object valie (can not unwrap Array values using this mechanism)
• Reading/writing is done using Jackson standard BeanDeserializer / BeanSerializer; or custom deserializer/serializer MUST explicitly support similar operation.
• Will not work with polymorphic type handling ("polymorphic deserialization")

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
boolean	enabled	Property that is usually only used when overriding (masking) annotations, using mix-in annotations.
java.lang.String	prefix	Optional property that can be used to add prefix String to use in front of names of properties that are unwrapped: this can be done for example to prevent name collisions.
java.lang.String	suffix	Optional property that can be used to add suffix String to append at the end of names of properties that are unwrapped: this can be done for example to prevent name collisions.

Element Detail

enabled

boolean enabled

Property that is usually only used when overriding (masking) annotations, using mix-in annotations. Otherwise default value of 'true' is fine, and value need not be explicitly included.

Default:

true

prefix

java.lang.String prefix

Optional property that can be used to add prefix String to use in front of names of properties that are unwrapped: this can be done for example to prevent name collisions.

Default:

""

suffix

java.lang.String suffix

Optional property that can be used to add suffix String to append at the end of names of properties that are unwrapped: this can be done for example to prevent name collisions.

Default:

""