com.fasterxml.jackson.databind.cfg

Class HandlerInstantiator

java.lang.Object

com.fasterxml.jackson.databind.cfg.HandlerInstantiator

public abstract class HandlerInstantiator
extends Object

Helper class used for handling details of creating handler instances (things like JsonSerializers, JsonDeserializers, various type handlers) of specific types. Actual handler type has been resolved at this point, so instantiator is strictly responsible for providing a configured instance by constructing and configuring a new instance, or possibly by recycling a shared instance. One use case is that of allowing dependency injection, which would otherwise be difficult to do.

Custom instances are allowed to return null to indicate that caller should use the default instantiation handling (which just means calling no-argument constructor via reflection).

Care has to be taken to ensure that if instance returned is shared, it will be thread-safe; caller will not synchronize access to returned instances.

Constructor Summary

Constructors

Constructor and Description
HandlerInstantiator()

Method Summary

Modifier and Type	Method and Description
Converter<?,?>	converterInstance(MapperConfig<?> config, Annotated annotated, Class<?> implClass) Method called to construct a Converter instance used for specified class.
abstract JsonDeserializer<?>	deserializerInstance(DeserializationConfig config, Annotated annotated, Class<?> deserClass) Method called to get an instance of deserializer of specified type.
Object	includeFilterInstance(SerializationConfig config, BeanPropertyDefinition forProperty, Class<?> filterClass) Method called to construct a Filter (any Object with implementation of equals(Object) that determines if given value is to be excluded (true) or included (false)) to be used based on JsonInclude annotation (or equivalent).
abstract KeyDeserializer	keyDeserializerInstance(DeserializationConfig config, Annotated annotated, Class<?> keyDeserClass) Method called to get an instance of key deserializer of specified type.
PropertyNamingStrategy	namingStrategyInstance(MapperConfig<?> config, Annotated annotated, Class<?> implClass) Method called to construct a NamingStrategy instance used for specified class.
ObjectIdGenerator<?>	objectIdGeneratorInstance(MapperConfig<?> config, Annotated annotated, Class<?> implClass) Method called to construct a ObjectIdHandler instance of specified type.
ObjectIdResolver	resolverIdGeneratorInstance(MapperConfig<?> config, Annotated annotated, Class<?> implClass)
abstract JsonSerializer<?>	serializerInstance(SerializationConfig config, Annotated annotated, Class<?> serClass) Method called to get an instance of serializer of specified type.
abstract TypeIdResolver	typeIdResolverInstance(MapperConfig<?> config, Annotated annotated, Class<?> resolverClass) Method called to get an instance of TypeIdResolver of specified type.
abstract TypeResolverBuilder<?>	typeResolverBuilderInstance(MapperConfig<?> config, Annotated annotated, Class<?> builderClass) Method called to get an instance of TypeResolverBuilder of specified type.
ValueInstantiator	valueInstantiatorInstance(MapperConfig<?> config, Annotated annotated, Class<?> resolverClass) Method called to construct an instance of ValueInstantiator of specified type.
VirtualBeanPropertyWriter	virtualPropertyWriterInstance(MapperConfig<?> config, Class<?> implClass) Method called to construct a VirtualBeanPropertyWriter instance of specified type.

Methods inherited from class java.lang.Object

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

Constructor Detail

HandlerInstantiator

public HandlerInstantiator()

Method Detail

deserializerInstance

public abstract JsonDeserializer<?> deserializerInstance(DeserializationConfig config,
                                                         Annotated annotated,
                                                         Class<?> deserClass)

Method called to get an instance of deserializer of specified type.

Parameters:

config - Deserialization configuration in effect

annotated - Element (Class, Method, Field, constructor parameter) that had annotation defining class of deserializer to construct (to allow implementation use information from other annotations)

deserClass - Class of deserializer instance to return

Returns:

Deserializer instance to use

keyDeserializerInstance

public abstract KeyDeserializer keyDeserializerInstance(DeserializationConfig config,
                                                        Annotated annotated,
                                                        Class<?> keyDeserClass)

Method called to get an instance of key deserializer of specified type.

Parameters:

config - Deserialization configuration in effect

annotated - Element (Class, Method, Field, constructor parameter) that had annotation defining class of key deserializer to construct (to allow implementation use information from other annotations)

keyDeserClass - Class of key deserializer instance to return

Returns:

Key deserializer instance to use

serializerInstance

public abstract JsonSerializer<?> serializerInstance(SerializationConfig config,
                                                     Annotated annotated,
                                                     Class<?> serClass)

Method called to get an instance of serializer of specified type.

Parameters:

config - Serialization configuration in effect

annotated - Element (Class, Method, Field) that had annotation defining class of serializer to construct (to allow implementation use information from other annotations)

serClass - Class of serializer instance to return

Returns:

Serializer instance to use

typeResolverBuilderInstance

public abstract TypeResolverBuilder<?> typeResolverBuilderInstance(MapperConfig<?> config,
                                                                   Annotated annotated,
                                                                   Class<?> builderClass)

Method called to get an instance of TypeResolverBuilder of specified type.

Parameters:

config - Mapper configuration in effect (either SerializationConfig or DeserializationConfig, depending on when instance is being constructed)

annotated - annotated Element (Class, Method, Field) that had annotation defining class of builder to construct (to allow implementation use information from other annotations)

builderClass - Class of builder instance to return

Returns:

TypeResolverBuilder instance to use

typeIdResolverInstance

public abstract TypeIdResolver typeIdResolverInstance(MapperConfig<?> config,
                                                      Annotated annotated,
                                                      Class<?> resolverClass)

Method called to get an instance of TypeIdResolver of specified type.

Parameters:

config - Mapper configuration in effect (either SerializationConfig or DeserializationConfig, depending on when instance is being constructed)

annotated - annotated Element (Class, Method, Field) that had annotation defining class of resolver to construct (to allow implementation use information from other annotations)

resolverClass - Class of resolver instance to return

Returns:

TypeResolverBuilder instance to use

valueInstantiatorInstance

public ValueInstantiator valueInstantiatorInstance(MapperConfig<?> config,
                                                   Annotated annotated,
                                                   Class<?> resolverClass)

Method called to construct an instance of ValueInstantiator of specified type.

objectIdGeneratorInstance

public ObjectIdGenerator<?> objectIdGeneratorInstance(MapperConfig<?> config,
                                                      Annotated annotated,
                                                      Class<?> implClass)

Method called to construct a ObjectIdHandler instance of specified type.

Since:

2.0

resolverIdGeneratorInstance

public ObjectIdResolver resolverIdGeneratorInstance(MapperConfig<?> config,
                                                    Annotated annotated,
                                                    Class<?> implClass)

namingStrategyInstance

public PropertyNamingStrategy namingStrategyInstance(MapperConfig<?> config,
                                                     Annotated annotated,
                                                     Class<?> implClass)

Method called to construct a NamingStrategy instance used for specified class.

Since:

2.1

converterInstance

public Converter<?,?> converterInstance(MapperConfig<?> config,
                                        Annotated annotated,
                                        Class<?> implClass)

Method called to construct a Converter instance used for specified class.

Since:

2.2

virtualPropertyWriterInstance

public VirtualBeanPropertyWriter virtualPropertyWriterInstance(MapperConfig<?> config,
                                                               Class<?> implClass)

Method called to construct a VirtualBeanPropertyWriter instance of specified type.

Since:

2.5

includeFilterInstance

public Object includeFilterInstance(SerializationConfig config,
                                    BeanPropertyDefinition forProperty,
                                    Class<?> filterClass)

Method called to construct a Filter (any Object with implementation of equals(Object) that determines if given value is to be excluded (true) or included (false)) to be used based on JsonInclude annotation (or equivalent).

Default implementation returns `null` to indicate that default instantiation (use zero-arg constructor of the filterClass) should be used.

Since:

2.9