com.fasterxml.jackson.core.type

Class WritableTypeId

java.lang.Object

com.fasterxml.jackson.core.type.WritableTypeId

public class WritableTypeId
extends Object

This is a simple value class used between core streaming and higher level databinding to pass information about type ids to write. Properties are exposed and mutable on purpose: they are only used for communication over serialization of a single value, and neither retained across calls nor shared between threads.

Usual usage pattern is such that instance of this class is passed on two calls that are needed for outputting type id (and possible additional wrapping, depending on format; JSON, for example, requires wrapping as type id is part of regular data): first, a "prefix" write (which usually includes actual id), performed before value write; and then matching "suffix" write after value serialization.

Since:

2.9

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	WritableTypeId.Inclusion Enumeration of values that matches enum `As` from annotation `JsonTypeInfo`: separate definition to avoid dependency between streaming core and annotations packages; also allows more flexibility in case new values needed at this level of internal API.

Field Summary

Fields

Modifier and Type	Field and Description
String	asProperty If type id is to be embedded as a regular property, name of the property; otherwise `null`.
Object	extra Optional additional information that generator may add during "prefix write", to be available on matching "suffix write".
Object	forValue Java object for which type id is being written.
Class<?>	forValueType (optional) Super-type of forValue to use for type id generation (if no explicit id passed): used instead of actual class of forValue in cases where we do not want to use the "real" type but something more generic, usually to work around specific problem with implementation type, or its deserializer.
Object	id Actual type id to use: usually {link java.lang.String}.
WritableTypeId.Inclusion	include Property used to indicate style of inclusion for this type id, in cases where no native type id may be used (either because format has none, like JSON; or because use of native type ids is disabled [with YAML]).
JsonToken	valueShape Information about intended shape of the value being written (that is, forValue); in case of structured values, start token of the structure; for scalars, value token.
boolean	wrapperWritten Flag that can be set to indicate that wrapper structure was written (during prefix-writing); used to determine if suffix requires matching close markers.

Constructor Summary

Constructors

Constructor and Description
WritableTypeId()
WritableTypeId(Object value, Class<?> valueType, JsonToken valueShape) Constructor used when calling a method for generating and writing Type Id, but where actual type to use for generating id is NOT the type of value (but its supertype).
WritableTypeId(Object value, JsonToken valueShape) Constructor used when calling a method for generating and writing Type Id; caller only knows value object and its intended shape.
WritableTypeId(Object value, JsonToken valueShape, Object id) Constructor used when calling a method for writing Type Id; caller knows value object, its intended shape as well as id to use; but not details of wrapping (if any).

Method Summary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

forValue

public Object forValue

Java object for which type id is being written. Not needed by default handling, but may be useful for customized format handling.

forValueType

public Class<?> forValueType

(optional) Super-type of forValue to use for type id generation (if no explicit id passed): used instead of actual class of forValue in cases where we do not want to use the "real" type but something more generic, usually to work around specific problem with implementation type, or its deserializer.

id

public Object id

Actual type id to use: usually {link java.lang.String}.

asProperty

public String asProperty

If type id is to be embedded as a regular property, name of the property; otherwise `null`.

NOTE: if "wrap-as-Object" is used, this does NOT contain property name to use but `null`.

include

public WritableTypeId.Inclusion include

Property used to indicate style of inclusion for this type id, in cases where no native type id may be used (either because format has none, like JSON; or because use of native type ids is disabled [with YAML]).

valueShape

public JsonToken valueShape

Information about intended shape of the value being written (that is, forValue); in case of structured values, start token of the structure; for scalars, value token. Main difference is between structured values (JsonToken.START_ARRAY, JsonToken.START_OBJECT) and scalars (JsonToken.VALUE_STRING): specific scalar type may not be important for processing.

wrapperWritten

public boolean wrapperWritten

Flag that can be set to indicate that wrapper structure was written (during prefix-writing); used to determine if suffix requires matching close markers.

extra

public Object extra

Optional additional information that generator may add during "prefix write", to be available on matching "suffix write".

Constructor Detail

WritableTypeId

public WritableTypeId()

WritableTypeId

public WritableTypeId(Object value,
                      JsonToken valueShape)

Constructor used when calling a method for generating and writing Type Id; caller only knows value object and its intended shape.

Parameters:

value - Actual value for which type information is written

valueShape - Serialize shape writer will use for value

WritableTypeId

public WritableTypeId(Object value,
                      Class<?> valueType,
                      JsonToken valueShape)

Constructor used when calling a method for generating and writing Type Id, but where actual type to use for generating id is NOT the type of value (but its supertype).

Parameters:

value - Actual value for which type information is written

valueType - Effective type of value to use for Type Id generation

valueShape - Serialize shape writer will use for value

WritableTypeId

public WritableTypeId(Object value,
                      JsonToken valueShape,
                      Object id)

Constructor used when calling a method for writing Type Id; caller knows value object, its intended shape as well as id to use; but not details of wrapping (if any).

Parameters:

value - Actual value for which type information is written

valueShape - Serialize shape writer will use for value

id - Actual type id to use if known; null if not