com.fasterxml.jackson.databind.deser

Class DeserializerFactory

java.lang.Object

com.fasterxml.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 JsonDeserializer 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(com.fasterxml.jackson.databind.DeserializationContext, com.fasterxml.jackson.databind.type.ArrayType, com.fasterxml.jackson.databind.BeanDescription)) and the other for other Java containers like Lists and Sets (createCollectionDeserializer(com.fasterxml.jackson.databind.DeserializationContext, com.fasterxml.jackson.databind.type.CollectionType, com.fasterxml.jackson.databind.BeanDescription)). 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(com.fasterxml.jackson.databind.DeserializationContext, com.fasterxml.jackson.databind.type.MapType, com.fasterxml.jackson.databind.BeanDescription)), and another for POJOs (createBeanDeserializer(com.fasterxml.jackson.databind.DeserializationContext, com.fasterxml.jackson.databind.JavaType, com.fasterxml.jackson.databind.BeanDescription). 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(com.fasterxml.jackson.databind.DeserializationConfig, com.fasterxml.jackson.databind.JavaType, com.fasterxml.jackson.databind.BeanDescription)
• For enumerated types (Enum) there is createEnumDeserializer(com.fasterxml.jackson.databind.DeserializationContext, com.fasterxml.jackson.databind.JavaType, com.fasterxml.jackson.databind.BeanDescription)
• For all other types, createBeanDeserializer(com.fasterxml.jackson.databind.DeserializationContext, com.fasterxml.jackson.databind.JavaType, com.fasterxml.jackson.databind.BeanDescription) is used.

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
DeserializerFactory()

Method Summary

Modifier and Type	Method and Description
abstract JsonDeserializer<?>	createArrayDeserializer(DeserializationContext ctxt, ArrayType type, BeanDescription beanDesc) Method called to create (or, for completely immutable deserializers, reuse) a deserializer that can convert JSON content into values of specified Java type.
abstract JsonDeserializer<Object>	createBeanDeserializer(DeserializationContext ctxt, JavaType type, BeanDescription beanDesc) 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 JsonDeserializer<Object>	createBuilderBasedDeserializer(DeserializationContext ctxt, JavaType type, BeanDescription beanDesc, Class<?> builderClass) Method called to create a deserializer that will use specified Builder class for building value instances.
abstract JsonDeserializer<?>	createCollectionDeserializer(DeserializationContext ctxt, CollectionType type, BeanDescription beanDesc)
abstract JsonDeserializer<?>	createCollectionLikeDeserializer(DeserializationContext ctxt, CollectionLikeType type, BeanDescription beanDesc)
abstract JsonDeserializer<?>	createEnumDeserializer(DeserializationContext ctxt, JavaType type, BeanDescription beanDesc)
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 JsonDeserializer<?>	createMapDeserializer(DeserializationContext ctxt, MapType type, BeanDescription beanDesc)
abstract JsonDeserializer<?>	createMapLikeDeserializer(DeserializationContext ctxt, MapLikeType type, BeanDescription beanDesc)
abstract JsonDeserializer<?>	createReferenceDeserializer(DeserializationContext ctxt, ReferenceType type, BeanDescription beanDesc)
abstract JsonDeserializer<?>	createTreeDeserializer(DeserializationConfig config, JavaType type, BeanDescription beanDesc) Method called to create and return a deserializer that can construct JsonNode(s) from JSON content.
abstract TypeDeserializer	findTypeDeserializer(DeserializationConfig config, JavaType baseType) Method called to find and create a type information deserializer for given base type, if one is needed.
abstract ValueInstantiator	findValueInstantiator(DeserializationContext ctxt, BeanDescription beanDesc) Method that is to find all creators (constructors, factory methods) for the bean type to deserialize.
abstract boolean	hasExplicitDeserializerFor(DeserializationConfig config, 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 JavaType	mapAbstractType(DeserializationConfig config, JavaType type) Method that can be called to try to resolve an abstract type (interface, abstract class) into a concrete type, or at least something "more concrete" (abstract class instead of interface).
abstract DeserializerFactory	withAbstractTypeResolver(AbstractTypeResolver resolver) Convenience method for creating a new factory instance with additional AbstractTypeResolver.
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(BeanDeserializerModifier modifier) Convenience method for creating a new factory instance with additional BeanDeserializerModifier.
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 Detail

NO_DESERIALIZERS

protected static final Deserializers[] NO_DESERIALIZERS

Constructor Detail

DeserializerFactory

public DeserializerFactory()

Method Detail

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(BeanDeserializerModifier modifier)

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

withAbstractTypeResolver

public abstract DeserializerFactory withAbstractTypeResolver(AbstractTypeResolver resolver)

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

withValueInstantiators

public abstract DeserializerFactory withValueInstantiators(ValueInstantiators instantiators)

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

mapAbstractType

public abstract JavaType mapAbstractType(DeserializationConfig config,
                                         JavaType type)
                                  throws JsonMappingException

Method that can be called to try to resolve an abstract type (interface, abstract class) into a concrete type, or at least something "more concrete" (abstract class instead of interface). Will either return passed type, or a more specific type.

Throws:

JsonMappingException

findValueInstantiator

public abstract ValueInstantiator findValueInstantiator(DeserializationContext ctxt,
                                                        BeanDescription beanDesc)
                                                 throws JsonMappingException

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

Throws:

JsonMappingException

createBeanDeserializer

public abstract JsonDeserializer<Object> createBeanDeserializer(DeserializationContext ctxt,
                                                                JavaType type,
                                                                BeanDescription beanDesc)
                                                         throws JsonMappingException

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

Throws:

JsonMappingException

createBuilderBasedDeserializer

public abstract JsonDeserializer<Object> createBuilderBasedDeserializer(DeserializationContext ctxt,
                                                                        JavaType type,
                                                                        BeanDescription beanDesc,
                                                                        Class<?> builderClass)
                                                                 throws JsonMappingException

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

Throws:

JsonMappingException

createEnumDeserializer

public abstract JsonDeserializer<?> createEnumDeserializer(DeserializationContext ctxt,
                                                           JavaType type,
                                                           BeanDescription beanDesc)
                                                    throws JsonMappingException

Throws:

JsonMappingException

createReferenceDeserializer

public abstract JsonDeserializer<?> createReferenceDeserializer(DeserializationContext ctxt,
                                                                ReferenceType type,
                                                                BeanDescription beanDesc)
                                                         throws JsonMappingException

Throws:

JsonMappingException

Since:

2.7

createTreeDeserializer

public abstract JsonDeserializer<?> createTreeDeserializer(DeserializationConfig config,
                                                           JavaType type,
                                                           BeanDescription beanDesc)
                                                    throws JsonMappingException

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

Throws:

JsonMappingException

createArrayDeserializer

public abstract JsonDeserializer<?> createArrayDeserializer(DeserializationContext ctxt,
                                                            ArrayType type,
                                                            BeanDescription beanDesc)
                                                     throws JsonMappingException

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

Throws:

JsonMappingException

createCollectionDeserializer

public abstract JsonDeserializer<?> createCollectionDeserializer(DeserializationContext ctxt,
                                                                 CollectionType type,
                                                                 BeanDescription beanDesc)
                                                          throws JsonMappingException

Throws:

JsonMappingException

createCollectionLikeDeserializer

public abstract JsonDeserializer<?> createCollectionLikeDeserializer(DeserializationContext ctxt,
                                                                     CollectionLikeType type,
                                                                     BeanDescription beanDesc)
                                                              throws JsonMappingException

Throws:

JsonMappingException

createMapDeserializer

public abstract JsonDeserializer<?> createMapDeserializer(DeserializationContext ctxt,
                                                          MapType type,
                                                          BeanDescription beanDesc)
                                                   throws JsonMappingException

Throws:

JsonMappingException

createMapLikeDeserializer

public abstract JsonDeserializer<?> createMapLikeDeserializer(DeserializationContext ctxt,
                                                              MapLikeType type,
                                                              BeanDescription beanDesc)
                                                       throws JsonMappingException

Throws:

JsonMappingException

createKeyDeserializer

public abstract KeyDeserializer createKeyDeserializer(DeserializationContext ctxt,
                                                      JavaType type)
                                               throws JsonMappingException

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)

Throws:

JsonMappingException

findTypeDeserializer

public abstract TypeDeserializer findTypeDeserializer(DeserializationConfig config,
                                                      JavaType baseType)
                                               throws JsonMappingException

Method called to find and create a type information deserializer for given base type, if one is needed. If not needed (no polymorphic handling configured for type), should return null.

Note that this method is usually only directly called for values of container (Collection, array, Map) types and root values, but not for bean property values.

Parameters:

baseType - Declared base type of the value to deserializer (actual deserializer type will be this type or its subtype)

Returns:

Type deserializer to use for given base type, if one is needed; null if not.

Throws:

JsonMappingException

hasExplicitDeserializerFor

public abstract boolean hasExplicitDeserializerFor(DeserializationConfig config,
                                                   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 Modules 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.

Since:

2.11