Package com.fasterxml.jackson.annotation

Annotation Type JsonDeserializeAs

@Target({ANNOTATION_TYPE,METHOD,FIELD,TYPE,PARAMETER}) @Retention(RUNTIME) public @interface JsonDeserializeAs
Annotation to indicate override of deserialization target type; a more specialized type (sub-type) than declared one. Can be used on types (Classes) or on properties (property accessors like "getters", "setters" and constructor parameters). Overrides can apply to:
  • value itself (for all types and properties)
  • content of structured types (array and Collection elements; Map values)
  • keys of Maps

To indicate that no override is to be used, Void.class is used as the marker (will use declared type) -- this is necessary as Annotation properties cannot have null values.

Example usage: 

 public class POJO {
   @JsonDeserializeAs(ValueImpl.class)
   public Value value;

   @JsonDeserializeAs(keys = KeyEnum.class, content = ValueImpl.class)
   public Map<Object, Object> props;
 }

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    Class<?>
    content
    Type to deserialize content entries (array and Collection elements, Map values) as, instead of type declared.
    Class<?>
    keys
    Type to deserialize Map keys as, instead of type declared.
    Class<?>
    value
    Type to deserialize values as, instead of type declared.

  • Element Details

    • value

      Class<?> value
      Type to deserialize values as, instead of type declared. Must be a sub-type of declared type; otherwise an exception may be thrown by deserializer.

      Bogus type Void is used to indicate that declared type is used as-is (i.e. this annotation property has no setting).

      Default:
      java.lang.Void.class

    • content

      Class<?> content
      Type to deserialize content entries (array and Collection elements, Map values) as, instead of type declared. Must be a sub-type of declared type; otherwise an exception may be thrown by deserializer.

      Bogus type Void is used to indicate that declared type is used as-is (i.e. this annotation property has no setting).

      Default:
      java.lang.Void.class

    • keys

      Class<?> keys
      Type to deserialize Map keys as, instead of type declared. Must be a sub-type of declared type; otherwise an exception may be thrown by deserializer.

      Bogus type Void is used to indicate that declared type is used as-is (i.e. this annotation property has no setting).

      Default:
      java.lang.Void.class