com.fasterxml.jackson.databind.cfg.HandlerInstantiator Maven / Gradle / Ivy
package com.fasterxml.jackson.databind.cfg;
import com.fasterxml.jackson.annotation.ObjectIdGenerator;
import com.fasterxml.jackson.annotation.ObjectIdResolver;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.deser.ValueInstantiator;
import com.fasterxml.jackson.databind.introspect.Annotated;
import com.fasterxml.jackson.databind.introspect.BeanPropertyDefinition;
import com.fasterxml.jackson.databind.jsontype.TypeIdResolver;
import com.fasterxml.jackson.databind.jsontype.TypeResolverBuilder;
import com.fasterxml.jackson.databind.ser.VirtualBeanPropertyWriter;
import com.fasterxml.jackson.databind.util.Converter;
/**
* Helper class used for handling details of creating handler instances (things
* like {@link JsonSerializer}s, {@link JsonDeserializer}s, 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.
*/
public abstract class HandlerInstantiator
{
/*
/**********************************************************
/* Public API
/**********************************************************
*/
/**
* Method called to get an instance of deserializer of specified type.
*
* @param config Deserialization configuration in effect
* @param annotated Element (Class, Method, Field, constructor parameter) that
* had annotation defining class of deserializer to construct (to allow
* implementation use information from other annotations)
* @param deserClass Class of deserializer instance to return
*
* @return Deserializer instance to use
*/
public abstract JsonDeserializer deserializerInstance(DeserializationConfig config,
Annotated annotated, Class deserClass);
/**
* Method called to get an instance of key deserializer of specified type.
*
* @param config Deserialization configuration in effect
* @param 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)
* @param keyDeserClass Class of key deserializer instance to return
*
* @return Key deserializer instance to use
*/
public abstract KeyDeserializer keyDeserializerInstance(DeserializationConfig config,
Annotated annotated, Class keyDeserClass);
/**
* Method called to get an instance of serializer of specified type.
*
* @param config Serialization configuration in effect
* @param annotated Element (Class, Method, Field) that
* had annotation defining class of serializer to construct (to allow
* implementation use information from other annotations)
* @param serClass Class of serializer instance to return
*
* @return Serializer instance to use
*/
public abstract JsonSerializer serializerInstance(SerializationConfig config,
Annotated annotated, Class serClass);
/**
* Method called to get an instance of TypeResolverBuilder of specified type.
*
* @param config Mapper configuration in effect (either SerializationConfig or
* DeserializationConfig, depending on when instance is being constructed)
* @param annotated annotated Element (Class, Method, Field) that
* had annotation defining class of builder to construct (to allow
* implementation use information from other annotations)
* @param builderClass Class of builder instance to return
*
* @return TypeResolverBuilder instance to use
*/
public abstract TypeResolverBuilder typeResolverBuilderInstance(MapperConfig config,
Annotated annotated, Class builderClass);
/**
* Method called to get an instance of TypeIdResolver of specified type.
*
* @param config Mapper configuration in effect (either SerializationConfig or
* DeserializationConfig, depending on when instance is being constructed)
* @param annotated annotated Element (Class, Method, Field) that
* had annotation defining class of resolver to construct (to allow
* implementation use information from other annotations)
* @param resolverClass Class of resolver instance to return
*
* @return TypeResolverBuilder instance to use
*/
public abstract TypeIdResolver typeIdResolverInstance(MapperConfig config,
Annotated annotated, Class resolverClass);
/**
* Method called to construct an instance of ValueInstantiator of specified type.
*/
public ValueInstantiator valueInstantiatorInstance(MapperConfig config,
Annotated annotated, Class resolverClass) {
return null;
}
/**
* Method called to construct a ObjectIdHandler instance of specified type.
*
* @since 2.0
*/
public ObjectIdGenerator objectIdGeneratorInstance(MapperConfig config,
Annotated annotated, Class implClass) {
return null;
}
public ObjectIdResolver resolverIdGeneratorInstance(MapperConfig config, Annotated annotated, Class implClass) {
return null;
}
/**
* Method called to construct a NamingStrategy instance used for specified
* class.
*
* @since 2.1
*/
public PropertyNamingStrategy namingStrategyInstance(MapperConfig config,
Annotated annotated, Class implClass) {
return null;
}
/**
* Method called to construct a Converter instance used for specified class.
*
* @since 2.2
*/
public Converter converterInstance(MapperConfig config,
Annotated annotated, Class implClass) {
return null;
}
/**
* Method called to construct a {@link VirtualBeanPropertyWriter} instance
* of specified type.
*
* @since 2.5
*/
public VirtualBeanPropertyWriter virtualPropertyWriterInstance(MapperConfig config,
Class implClass) {
return null;
}
/**
* 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
* {@link com.fasterxml.jackson.annotation.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
*/
public Object includeFilterInstance(SerializationConfig config,
BeanPropertyDefinition forProperty, Class filterClass) {
return null;
}
}