Module tools.jackson.databind

Package tools.jackson.databind.deser

Class DeserializerFactory

java.lang.Object

tools.jackson.databind.deser.DeserializerFactory

Direct Known Subclasses:

BasicDeserializerFactory

public abstract class DeserializerFactory
extends Object

Abstract class that defines API used by DeserializationContext to construct actual ValueDeserializer instances (which are then cached by context and/or dedicated cache).

Since there are multiple broad categories of deserializers, there are multiple factory methods:

• For JSON "Array" type, we need 2 methods: one to deal with expected Java arrays (createArrayDeserializer(tools.jackson.databind.DeserializationContext, tools.jackson.databind.type.ArrayType, tools.jackson.databind.BeanDescription.Supplier)) and the other for other Java containers like Lists and Sets (createCollectionDeserializer(tools.jackson.databind.DeserializationContext, tools.jackson.databind.type.CollectionType, tools.jackson.databind.BeanDescription.Supplier)). Actually there is also a third method for "Collection-like" types; things like Scala collections that act like JDK collections but do not implement same interfaces.
• For JSON "Object" type, we need 2 methods: one to deal with expected Java Maps (createMapDeserializer(tools.jackson.databind.DeserializationContext, tools.jackson.databind.type.MapType, tools.jackson.databind.BeanDescription.Supplier)), and another for POJOs (createBeanDeserializer(tools.jackson.databind.DeserializationContext, tools.jackson.databind.JavaType, tools.jackson.databind.BeanDescription.Supplier). As an additional twist there is also a callback for "Map-like" types, mostly to make it possible to support Scala Maps (which are NOT JDK Map compatible).
• For Tree Model (JsonNode) properties there is createTreeDeserializer(tools.jackson.databind.DeserializationConfig, tools.jackson.databind.JavaType, tools.jackson.databind.BeanDescription.Supplier)
• For enumerated types (Enum) there is createEnumDeserializer(tools.jackson.databind.DeserializationContext, tools.jackson.databind.JavaType, tools.jackson.databind.BeanDescription.Supplier)
• For all other types, createBeanDeserializer(tools.jackson.databind.DeserializationContext, tools.jackson.databind.JavaType, tools.jackson.databind.BeanDescription.Supplier) is used.

Field Summary

Fields

Modifier and Type	Field	Description
protected static final Deserializers[]	NO_DESERIALIZERS

Constructor Summary

Constructors

Constructor	Description
DeserializerFactory()

Method Summary

Modifier and Type	Method	Description
abstract ValueDeserializer<?>	createArrayDeserializer(DeserializationContext ctxt, ArrayType type, BeanDescription.Supplier beanDescRef)	Method called to create (or, for completely immutable deserializers, reuse) a deserializer that can convert JSON content into values of specified Java type.
abstract ValueDeserializer<Object>	createBeanDeserializer(DeserializationContext ctxt, JavaType type, BeanDescription.Supplier beanDescRef)	Method called to create (or, for completely immutable deserializers, reuse) a deserializer that can convert JSON content into values of specified Java "bean" (POJO) type.
abstract ValueDeserializer<Object>	createBuilderBasedDeserializer(DeserializationContext ctxt, JavaType type, BeanDescription.Supplier beanDescRef, Class<?> builderClass)	Method called to create a deserializer that will use specified Builder class for building value instances.
abstract ValueDeserializer<?>	createCollectionDeserializer(DeserializationContext ctxt, CollectionType type, BeanDescription.Supplier beanDescRef)
abstract ValueDeserializer<?>	createCollectionLikeDeserializer(DeserializationContext ctxt, CollectionLikeType type, BeanDescription.Supplier beanDescRef)
abstract ValueDeserializer<?>	createEnumDeserializer(DeserializationContext ctxt, JavaType type, BeanDescription.Supplier beanDescRef)
abstract KeyDeserializer	createKeyDeserializer(DeserializationContext ctxt, JavaType type)	Method called to find if factory knows how to create a key deserializer for specified type; currently this means checking if a module has registered possible deserializers.
abstract ValueDeserializer<?>	createMapDeserializer(DeserializationContext ctxt, MapType type, BeanDescription.Supplier beanDescRef)
abstract ValueDeserializer<?>	createMapLikeDeserializer(DeserializationContext ctxt, MapLikeType type, BeanDescription.Supplier beanDescRef)
abstract ValueDeserializer<?>	createReferenceDeserializer(DeserializationContext ctxt, ReferenceType type, BeanDescription.Supplier beanDescRef)
abstract ValueDeserializer<?>	createTreeDeserializer(DeserializationConfig config, JavaType type, BeanDescription.Supplier beanDescRef)	Method called to create and return a deserializer that can construct JsonNode(s) from JSON content.
abstract ValueInstantiator	findValueInstantiator(DeserializationContext ctxt, BeanDescription.Supplier beanDescRef)	Method that is to find all creators (constructors, factory methods) for the bean type to deserialize.
abstract boolean	hasExplicitDeserializerFor(DatabindContext ctxt, Class<?> valueType)	Method that can be used to check if databind module has explicitly declared deserializer for given (likely JDK) type, explicit meaning that there is specific deserializer for given type as opposed to auto-generated "Bean" deserializer.
abstract DeserializerFactory	withAdditionalDeserializers(Deserializers additional)	Convenience method for creating a new factory instance with additional deserializer provider.
abstract DeserializerFactory	withAdditionalKeyDeserializers(KeyDeserializers additional)	Convenience method for creating a new factory instance with additional KeyDeserializers.
abstract DeserializerFactory	withDeserializerModifier(ValueDeserializerModifier modifier)	Convenience method for creating a new factory instance with additional ValueDeserializerModifier.
abstract DeserializerFactory	withValueInstantiators(ValueInstantiators instantiators)	Convenience method for creating a new factory instance with additional ValueInstantiators.

Methods inherited from class java.lang.Object

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

Field Details

NO_DESERIALIZERS

protected static final Deserializers[] NO_DESERIALIZERS

Constructor Details

DeserializerFactory

public DeserializerFactory()

Method Details

findValueInstantiator

public abstract ValueInstantiator findValueInstantiator(DeserializationContext ctxt,
 BeanDescription.Supplier beanDescRef)

Method that is to find all creators (constructors, factory methods) for the bean type to deserialize.

createBeanDeserializer

public abstract ValueDeserializer<Object> createBeanDeserializer(DeserializationContext ctxt,
 JavaType type,
 BeanDescription.Supplier beanDescRef)

Method called to create (or, for completely immutable deserializers, reuse) a deserializer that can convert JSON content into values of specified Java "bean" (POJO) type. At this point it is known that the type is not otherwise recognized as one of structured types (array, Collection, Map) or a well-known JDK type (enum, primitives/wrappers, String); this method only gets called if other options are exhausted. This also means that this method can be overridden to add support for custom types.

Parameters:

type - Type to be deserialized

createBuilderBasedDeserializer

public abstract ValueDeserializer<Object> createBuilderBasedDeserializer(DeserializationContext ctxt,
 JavaType type,
 BeanDescription.Supplier beanDescRef,
 Class<?> builderClass)

Method called to create a deserializer that will use specified Builder class for building value instances.

createEnumDeserializer

public abstract ValueDeserializer<?> createEnumDeserializer(DeserializationContext ctxt,
 JavaType type,
 BeanDescription.Supplier beanDescRef)

createReferenceDeserializer

public abstract ValueDeserializer<?> createReferenceDeserializer(DeserializationContext ctxt,
 ReferenceType type,
 BeanDescription.Supplier beanDescRef)

createTreeDeserializer

public abstract ValueDeserializer<?> createTreeDeserializer(DeserializationConfig config,
 JavaType type,
 BeanDescription.Supplier beanDescRef)

Method called to create and return a deserializer that can construct JsonNode(s) from JSON content.

createArrayDeserializer

public abstract ValueDeserializer<?> createArrayDeserializer(DeserializationContext ctxt,
 ArrayType type,
 BeanDescription.Supplier beanDescRef)

Method called to create (or, for completely immutable deserializers, reuse) a deserializer that can convert JSON content into values of specified Java type.

Parameters:

type - Type to be deserialized

createCollectionDeserializer

public abstract ValueDeserializer<?> createCollectionDeserializer(DeserializationContext ctxt,
 CollectionType type,
 BeanDescription.Supplier beanDescRef)

createCollectionLikeDeserializer

public abstract ValueDeserializer<?> createCollectionLikeDeserializer(DeserializationContext ctxt,
 CollectionLikeType type,
 BeanDescription.Supplier beanDescRef)

createMapDeserializer

public abstract ValueDeserializer<?> createMapDeserializer(DeserializationContext ctxt,
 MapType type,
 BeanDescription.Supplier beanDescRef)

createMapLikeDeserializer

public abstract ValueDeserializer<?> createMapLikeDeserializer(DeserializationContext ctxt,
 MapLikeType type,
 BeanDescription.Supplier beanDescRef)

createKeyDeserializer

public abstract KeyDeserializer createKeyDeserializer(DeserializationContext ctxt,
 JavaType type)

Method called to find if factory knows how to create a key deserializer for specified type; currently this means checking if a module has registered possible deserializers.

Returns:

Key deserializer to use for specified type, if one found; null if not (and default key deserializer should be used)

hasExplicitDeserializerFor

public abstract boolean hasExplicitDeserializerFor(DatabindContext ctxt,
 Class<?> valueType)

Method that can be used to check if databind module has explicitly declared deserializer for given (likely JDK) type, explicit meaning that there is specific deserializer for given type as opposed to auto-generated "Bean" deserializer. Factory itself will check for known JDK-provided types, but registered JacksonModules are also called to see if they might provide explicit deserializer.

Main use for this method is with Safe Default Typing (and generally Safe Polymorphic Deserialization), during which it is good to be able to check that given raw type is explicitly supported and as such "known type" (as opposed to potentially dangerous "gadget type" which could be exploited).

This matches Deserializers.Base.hasDeserializerFor(Class) method, which is the mechanism used to determine if a Module might provide an explicit deserializer instead of core databind.

withAdditionalDeserializers

public abstract DeserializerFactory withAdditionalDeserializers(Deserializers additional)

Convenience method for creating a new factory instance with additional deserializer provider.

withAdditionalKeyDeserializers

public abstract DeserializerFactory withAdditionalKeyDeserializers(KeyDeserializers additional)

Convenience method for creating a new factory instance with additional KeyDeserializers.

withDeserializerModifier

public abstract DeserializerFactory withDeserializerModifier(ValueDeserializerModifier modifier)

Convenience method for creating a new factory instance with additional ValueDeserializerModifier.

withValueInstantiators

public abstract DeserializerFactory withValueInstantiators(ValueInstantiators instantiators)

Convenience method for creating a new factory instance with additional ValueInstantiators.