com.fasterxml.jackson.annotation

Annotation Type JsonInclude

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

Annotation used to indicate when value of the annotated property (when used for a field, method or constructor parameter), or all properties of the annotated class, is to be serialized. Without annotation property values are always included, but by using this annotation one can specify simple exclusion rules to reduce amount of properties to write out.

Note that the main inclusion criteria (one annotated with value()) is checked on Java object level, for the annotated type, and NOT on JSON output -- so even with JsonInclude.Include.NON_NULL it is possible that JSON null values are output, if object reference in question is not `null`. An example is AtomicReference instance constructed to reference null value: such a value would be serialized as JSON null, and not filtered out.

To base inclusion on value of contained value(s), you will typically also need to specify content() annotation; for example, specifying only value() as JsonInclude.Include.NON_EMPTY for a {link java.util.List} would exclude Lists with no Java elements, but would include Lists with `null` elements. To exclude Lists with only nulls, you would use both annotations like so:

public class Bean {
   @JsonInclude(value=Include.NON_EMPTY, content=Include.NON_NULL)
   public List<String> entries;
}

Similarly you could further exclude Lists, Maps or arrays that only contain "empty" elements, or "non-default" values (see JsonInclude.Include.NON_EMPTY and JsonInclude.Include.NON_DEFAULT for more details).

Since:

2.0

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
JsonInclude.Include	content Inclusion rule to use for entries ("content") of annotated Maps; defaults to JsonInclude.Include.ALWAYS.
JsonInclude.Include	value Inclusion rule to use for instances (values) of types (Classes) or properties annotated.

Element Detail

value

public abstract JsonInclude.Include value

Inclusion rule to use for instances (values) of types (Classes) or properties annotated.

Default:

com.fasterxml.jackson.annotation.JsonInclude.Include.ALWAYS

content

public abstract JsonInclude.Include content

Inclusion rule to use for entries ("content") of annotated Maps; defaults to JsonInclude.Include.ALWAYS.

Since:

2.5

Default:

com.fasterxml.jackson.annotation.JsonInclude.Include.ALWAYS