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

    • Element Detail

      • value

        public abstract JsonInclude.Include value
        Inclusion rule to use for instances (values) of types (Classes) or properties annotated; defaults to JsonInclude.Include.ALWAYS.
        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

      • valueFilter

        public abstract Class<?> valueFilter
        Specifies type of "Filter Object" to use in case value() is JsonInclude.Include.CUSTOM: if so, an instance is created by calling HandlerInstantiator (of ObjectMapper), which by default simply calls zero-argument constructor of the Filter Class.
        Since:
        2.9
        Default:
        java.lang.Void.class

      • contentFilter

        public abstract Class<?> contentFilter
        Specifies type of "Filter Object" to use in case content() is JsonInclude.Include.CUSTOM: if so, an instance is created by calling HandlerInstantiator (of ObjectMapper), which by default simply calls zero-argument constructor of the Filter Class.
        Since:
        2.9
        Default:
        java.lang.Void.class

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