# Package com.fasterxml.jackson.annotation

Public core annotations, most of which are used to configure how Data Mapping/Binding works.

See: Description

Interface Summary
JacksonAnnotationValue<A extends Annotation>: Marker interface used by value classes like `JsonFormat.Value` that are used to contain information from one of Jackson annotations, and can be directly instantiated from those annotations, as well as programmatically constructed and possibly merged.
ObjectIdResolver: Definition of API used for resolving actual Java object from Object Identifiers (as annotated using `JsonIdentityInfo`).

Class Summary
JacksonInject.Value: Helper class used to contain information from a single `JacksonInject` annotation, as well as to provide possible overrides from non-annotation sources.
JsonAutoDetect.Value: Helper class used to contain information from a single `JsonIgnoreProperties` annotation, as well as to provide possible overrides from non-annotation sources.
JsonFormat.Features: Helper class that encapsulates information equivalent to `Boolean` valued `EnumMap`.
JsonFormat.Value: Helper class used to contain information from a single `JsonFormat` annotation.
JsonIgnoreProperties.Value: Helper class used to contain information from a single `JsonIgnoreProperties` annotation, as well as to provide possible overrides from non-annotation sources.
JsonInclude.Value: Helper class used to contain information from a single `JsonInclude` annotation.
JsonIncludeProperties.Value: Helper class used to contain information from a single `JsonIncludeProperties` annotation, as well as to provide possible overrides from non-annotation sources.
JsonSetter.Value: Helper class used to contain information from a single `JsonSetter` annotation, as well as to provide possible overrides from non-annotation sources.
JsonTypeInfo.None: Deprecated Since 2.5, use any Annotation type (such as `JsonTypeInfo`), if such behavior is needed; this is rarely necessary.
JsonTypeInfo.Value
ObjectIdGenerator<T>: Definition of API used for constructing Object Identifiers (as annotated using `JsonIdentityInfo`).
ObjectIdGenerator.IdKey: Simple key class that can be used as a key for ObjectId-to-POJO mappings, when multiple ObjectId types and scopes are used.

ObjectIdGenerators

Container class for standard `ObjectIdGenerator` implementations: `ObjectIdGenerators.IntSequenceGenerator` `ObjectIdGenerators.PropertyGenerator` `ObjectIdGenerators.StringIdGenerator` (since 2.7) `ObjectIdGenerators.UUIDGenerator` NOTE: `ObjectIdGenerators.PropertyGenerator` applicability is limited in one case: it can only be used on polymorphic base types (ones indicated using `JsonTypeInfo` or default typing) via class annotations: property annotation will fail due to lack of access to property, needed to determine type of Object Id for deserialization.

ObjectIdGenerators.IntSequenceGenerator: Simple sequence-number based generator, which uses basic Java `int`s (starting with value 1) as Object Identifiers.
ObjectIdGenerators.None: Abstract marker class used to allow explicitly specifying that no generator is used; which also implies that no Object Id is to be included or used.
ObjectIdGenerators.PropertyGenerator: Abstract place-holder class which is used to denote case where Object Identifier to use comes from a POJO property (getter method or field).
ObjectIdGenerators.StringIdGenerator: Implementation that will accept arbitrary (but unique) String Ids on deserialization, and (by default) use random UUID generation similar to `ObjectIdGenerators.UUIDGenerator` for generation ids.
ObjectIdGenerators.UUIDGenerator: Implementation that just uses `UUID`s as reliably unique identifiers: downside is that resulting String is 36 characters long.
SimpleObjectIdResolver: Simple implementation of `ObjectIdResolver`

Enum Summary
JsonAutoDetect.Visibility: Enumeration for possible visibility thresholds (minimum visibility) that can be used to limit which methods (and fields) are auto-detected.
JsonCreator.Mode: Enumeration of possible `JsonCreator.mode()` values available.
JsonFormat.Feature: Set of features that can be enabled/disabled for property annotated.
JsonFormat.Shape: Value enumeration used for indicating preferred Shape; translates loosely to JSON types, with some extra values to indicate less precise choices (i.e. allowing one of multiple actual shapes)
JsonInclude.Include: Enumeration used with `JsonInclude` to define which properties of Java Beans are to be included in serialization.
JsonProperty.Access: Various options for `JsonProperty.access()` property, specifying how property may be accessed during serialization ("read") and deserialization ("write") (note that the direction of read and write is from perspective of the property, not from external data format: this may be confusing in some contexts).
JsonTypeInfo.As: Definition of standard type inclusion mechanisms for type metadata.
JsonTypeInfo.Id: Definition of different type identifiers that can be included in JSON during serialization, and used for deserialization.
Nulls: Enumeration used with `JsonSetter` (for properties `nulls` and `contentNulls`) to define how explicit `null` values from input (if input format has the concept; JSON, for example does) are handled.
OptBoolean: Optional Boolean value ("nullean").
PropertyAccessor: Enumeration used to define kinds of elements (called "property accessors") that annotations like `JsonAutoDetect` apply to.

Annotation Types Summary
JacksonAnnotation: Meta-annotation (annotations used on other annotations) used for marking all annotations that are part of Jackson package.
JacksonAnnotationsInside: Meta-annotation (annotations used on other annotations) used for indicating that instead of using target annotation (annotation annotated with this annotation), Jackson should use meta-annotations it has.
JacksonInject: Jackson-specific annotation used for indicating that value of annotated property will be "injected", i.e. set based on value configured by `ObjectMapper` (usually on per-call basis).
JsonAlias: Annotation that can be used to define one or more alternative names for a property, accepted during deserialization as alternative to the official name.
JsonAnyGetter: Marker annotation that can be used to define a non-static, no-argument method to be an "any getter"; accessor for getting a set of key/value pairs, to be serialized as part of containing POJO (similar to unwrapping) along with regular property values it has.
JsonAnySetter: Marker annotation that can be used to define a logical "any setter" mutator -- either using non-static two-argument method (first argument name of property, second value to set) or a field (of type `Map` or POJO) - to be used as a "fallback" handler for all otherwise unrecognized properties found from JSON content.
JsonAutoDetect: Class annotation that can be used to define which kinds of Methods are to be detected by auto-detection, and with what minimum access level.
JsonBackReference: Annotation used to indicate that associated property is part of two-way linkage between fields; and that its role is "child" (or "back") link.
JsonClassDescription: Annotation used to define a human-readable description for annotated type (class).
JsonCreator: Marker annotation that can be used to define constructors and factory methods as one to use for instantiating new instances of the associated class.
JsonEnumDefaultValue: Marker annotation that can be used to define a default value used when trying to deserialize unknown Enum values.
JsonFilter: Annotation used to indicate which logical filter is to be used for filtering out properties of type (class) annotated; association made by this annotation declaring ids of filters, and `com.fasterxml.jackson.databind.ObjectMapper` (or objects it delegates to) providing matching filters by id.
JsonFormat: General-purpose annotation used for configuring details of how values of properties are to be serialized.
JsonGetter: Marker annotation that can be used to define a non-static, no-argument value-returning (non-void) method to be used as a "getter" for a logical property.
JsonIdentityInfo: Annotation used for indicating that values of annotated type or property should be serializing so that instances either contain additional object identifier (in addition actual object properties), or as a reference that consists of an object id that refers to a full serialization.
JsonIdentityReference: Optional annotation that can be used for customizing details of a reference to Objects for which "Object Identity" is enabled (see `JsonIdentityInfo`).
JsonIgnore: Marker annotation that indicates that the logical property that the accessor (field, getter/setter method or Creator parameter [of `JsonCreator`-annotated constructor or factory method]) is to be ignored by introspection-based serialization and deserialization functionality.
JsonIgnoreProperties: Annotation that can be used to either suppress serialization of properties (during serialization), or ignore processing of JSON properties read (during deserialization).
JsonIgnoreType: Marker annotation that indicates that all properties that have type annotated with this annotation are to be ignored during serialization and deserialization.
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.
JsonIncludeProperties: Annotation that can be used to either only include serialization of properties (during serialization), or only include processing of JSON properties read (during deserialization).
JsonKey: Marker annotation that indicates that the value of annotated accessor (either field or "getter" method [a method with non-void return type, no args]) is to be used as the single value to serialize for the instance.
JsonManagedReference: Annotation used to indicate that annotated property is part of two-way linkage between fields; and that its role is "parent" (or "forward") link.
JsonMerge: Annotation to specify whether annotated property value should use "merging" approach: merging meaning that the current value is first accessed (with a getter or field) and then modified with incoming data.

JsonProperty

Marker annotation that can be used to define a non-static method as a "setter" or "getter" for a logical property accessor (depending on its signature), or a non-static Object field to be used (serialized, deserialized) as a logical property (to assign value or get value from) Value ("") indicates that the name of field (or, derived name of an accessor method (setter / getter)) is to be used as the property name without any modifications; a non-empty value can be used to specify a different name.

JsonPropertyDescription: Annotation used to define a human-readable description for a logical property.
JsonPropertyOrder: Annotation that can be used to define ordering (possibly partial) to use when serializing object properties.
JsonRawValue: Marker annotation that indicates that the annotated method or field should be serialized by including literal String value of the property as is, without quoting of characters.
JsonRootName: Annotation similar to `javax.xml.bind.annotation.XmlRootElement`, used to indicate name to use for root-level wrapping, if wrapping is enabled.
JsonSetter: Annotation that can be used to define a non-static, single-argument method to be used as a "setter" for a logical property as an alternative to recommended `JsonProperty` annotation; or (as of 2.9 and later), specify additional aspects of the assigning property a value during serialization.
JsonSubTypes: Annotation used with `JsonTypeInfo` to indicate subtypes of serializable polymorphic types, and to associate logical names used within JSON content (which is more portable than using physical Java class names).
JsonSubTypes.Type: Definition of a subtype, along with optional name(s).
JsonTypeId: Marker annotation that can be used on a property accessor (field, getter or setter, constructor parameter) to indicate that the property is to contain type id to use when including polymorphic type information.
JsonTypeInfo: Annotation used for configuring details of if and how type information is used with JSON serialization and deserialization, to preserve information about actual class of Object instances.
JsonTypeName: Annotation used for binding logical name that the annotated class has.
JsonUnwrapped: Annotation used to indicate that a POJO-valued property should be serialized "unwrapped" -- that is, if it would be serialized as Object value, its properties are instead included as properties of its containing Object -- and deserialized reproducing "missing" structure.
JsonValue: Marker annotation that indicates that the value of annotated accessor (either field or "getter" method [a method with non-void return type, no args]) is to be used as the single value to serialize for the instance, instead of the usual method of collecting properties of value.
JsonView: Annotation used for indicating view(s) that the property that is defined by method or field annotated is part of.

## Package com.fasterxml.jackson.annotation Description

Public core annotations, most of which are used to configure how Data Mapping/Binding works. Annotations in this package can only have dependencies to non-annotation classes in Core package; annotations that have dependencies to Mapper classes are included in Mapper module (under `org.codehaus.jackson.map.annotate`). Also contains parameter types (mostly enums) needed by annotations.

Note that prior versions (1.x) contained these annotations within 'core' jar, as part of Streaming API.