org.codehaus.jackson.map.Deserializers Maven / Gradle / Ivy
package org.codehaus.jackson.map;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.map.type.*;
import org.codehaus.jackson.type.JavaType;
/**
* Interface that defines API for simple extensions that can provide additional deserializers
* for various types. Access is by a single callback method; instance is to either return
* a configured {@link JsonDeserializer} for specified type, or null to indicate that it
* does not support handling of the type. In latter case, further calls can be made
* for other providers; in former case returned deserializer is used for handling of
* instances of specified type.
*
* Unlike with {@link Serializers}, multiple different methods are used since different
* kinds of types typically require different kinds of inputs.
*
* @since 1.7
*/
public interface Deserializers
{
/**
* Method called to locate constructor for specified array type.
*
* Deserializer for element type may be passed, if configured explicitly at higher level (by
* annotations, typically), but usually are not.
* Type deserializer for element is passed if one is needed based on contextual information
* (annotations on declared element class; or on field or method type is associated with).
*
* @param type Type of array instances to deserialize
* @param config Configuration in effect
* @param provider Provider that can be used to locate deserializer for component type (if
* one not provided, or needs to be overridden)
* @param property Property that contains array value (null for root values)
* @param elementTypeDeserializer If element type needs polymorphic type handling, this is
* the type information deserializer to use; should usually be used as is when constructing
* array deserializer.
* @param elementDeserializer Deserializer to use for elements, if explicitly defined (by using
* annotations, for exmple). May be null, in which case it should be resolved here (or using
* {@link ResolvableDeserializer} callback)
*
* @return Deserializer to use for the type; or null if this provider does not know how to construct it
*/
public JsonDeserializer findArrayDeserializer(ArrayType type, DeserializationConfig config,
DeserializerProvider provider,
BeanProperty property,
TypeDeserializer elementTypeDeserializer, JsonDeserializer elementDeserializer)
throws JsonMappingException;
/**
* Method called to locate constructor for specified {@link java.util.Collection} (List, Set etc) type.
*
* Deserializer for element type may be passed, if configured explicitly at higher level (by
* annotations, typically), but usually are not.
* Type deserializer for element is passed if one is needed based on contextual information
* (annotations on declared element class; or on field or method type is associated with).
*
* @param type Type of collection instances to deserialize
* @param config Configuration in effect
* @param provider Provider that can be used to locate dependant deserializers if and as necessary
* (but note that in many cases resolution must be deferred by using {@link ResolvableDeserializer} callback)
* @param property Property that contains array value (null for root values)
* @param beanDesc Definition of the enumeration type that contains class annotations and
* other information typically needed for building deserializers (note: always instance
* of {@link org.codehaus.jackson.map.introspect.BasicBeanDescription})
* @param elementTypeDeserializer If element type needs polymorphic type handling, this is
* the type information deserializer to use; should usually be used as is when constructing
* array deserializer.
* @param elementDeserializer Deserializer to use for elements, if explicitly defined (by using
* annotations, for exmple). May be null, in which case it should be resolved here (or using
* {@link ResolvableDeserializer} callback)
*
* @return Deserializer to use for the type; or null if this provider does not know how to construct it
*/
public JsonDeserializer findCollectionDeserializer(CollectionType type, DeserializationConfig config,
DeserializerProvider provider,
BeanDescription beanDesc,
BeanProperty property,
TypeDeserializer elementTypeDeserializer, JsonDeserializer elementDeserializer)
throws JsonMappingException;
/**
* Method called to locate deserializer for specified {@link java.lang.Enum} type.
*
* @param type Type of {@link java.lang.Enum} instances to deserialize
* @param config Configuration in effect
* @param beanDesc Definition of the enumeration type that contains class annotations and
* other information typically needed for building deserializers (note: always instance
* of {@link org.codehaus.jackson.map.introspect.BasicBeanDescription})
*
* @return Deserializer to use for the type; or null if this provider does not know how to construct it
*/
public JsonDeserializer findEnumDeserializer(Class type, DeserializationConfig config,
BeanDescription beanDesc,
BeanProperty property)
throws JsonMappingException;
/**
* Method called to locate deserializer for specified {@link java.util.Map} type.
*
* Deserializer for element type may be passed, if configured explicitly at higher level (by
* annotations, typically), but usually are not.
* Type deserializer for element is passed if one is needed based on contextual information
* (annotations on declared element class; or on field or method type is associated with).
*
* Similarly, a {@link KeyDeserializer} may be passed, but this is only done if there is
* a specific configuration override (annotations) to indicate instance to use. Otherwise
* null is passed, and key deserializer needs to be obtained using {@link DeserializerProvider}
*
* @param type Type of {@link java.util.Map} instances to deserialize
* @param config Configuration in effect
* @param provider Provider that can be used to locate dependant deserializers if and as necessary
* (but note that in many cases resolution must be deferred by using {@link ResolvableDeserializer} callback)
* @param beanDesc Definition of the enumeration type that contains class annotations and
* other information typically needed for building deserializers (note: always instance
* of {@link org.codehaus.jackson.map.introspect.BasicBeanDescription})
* @param keyDeserializer Key deserializer use, if it is defined via annotations or other configuration;
* null if default key deserializer for key type can be used.
* @param elementTypeDeserializer If element type needs polymorphic type handling, this is
* the type information deserializer to use; should usually be used as is when constructing
* array deserializer.
* @param elementDeserializer Deserializer to use for elements, if explicitly defined (by using
* annotations, for exmple). May be null, in which case it should be resolved here (or using
* {@link ResolvableDeserializer} callback)
*
* @return Deserializer to use for the type; or null if this provider does not know how to construct it
*/
public JsonDeserializer findMapDeserializer(MapType type, DeserializationConfig config,
DeserializerProvider provider,
BeanDescription beanDesc,
BeanProperty property,
KeyDeserializer keyDeserializer,
TypeDeserializer elementTypeDeserializer, JsonDeserializer elementDeserializer)
throws JsonMappingException;
/**
* Method called to locate deserializer for specified JSON tree node type.
*
* @param nodeType Specific type of JSON tree nodes to deserialize (subtype of {@link org.codehaus.jackson.JsonNode})
* @param config Configuration in effect
*
* @return Deserializer to use for the type; or null if this provider does not know how to construct it
*/
public JsonDeserializer findTreeNodeDeserializer(Class nodeType, DeserializationConfig config,
BeanProperty property)
throws JsonMappingException;
/**
* Method called to locate deserializer for specified value type which does not belong to any other
* category (not an Enum, Collection, Map, Array or tree node)
*
* @param type Bean type to deserialize
* @param config Configuration in effect
* @param provider Provider that can be used to locate dependant deserializers if and as necessary
* (but note that in many cases resolution must be deferred by using {@link ResolvableDeserializer} callback)
* @param beanDesc Definition of the enumeration type that contains class annotations and
* other information typically needed for building deserializers (note: always instance
* of {@link org.codehaus.jackson.map.introspect.BasicBeanDescription})
*
* @return Deserializer to use for the type; or null if this provider does not know how to construct it
*/
public JsonDeserializer findBeanDeserializer(JavaType type, DeserializationConfig config,
DeserializerProvider provider, BeanDescription beanDesc,
BeanProperty property)
throws JsonMappingException;
/*
/**********************************************************
/* Helper classes
/**********************************************************
*/
/**
* Basic {@link Deserializers} implementation that implements all methods but provides
* no deserializers. Its main purpose is to serve as a base class so that
* sub-classes only need to override methods they need, as most of the time some
* of methods are not needed (especially enumeration and array deserializers are
* very rarely overridde).
*
* @since 1.7
*/
public static class None implements Deserializers
{
@Override
public JsonDeserializer findArrayDeserializer(ArrayType type, DeserializationConfig config,
DeserializerProvider provider,
BeanProperty property,
TypeDeserializer elementTypeDeserializer, JsonDeserializer elementDeserializer)
throws JsonMappingException
{
return null;
}
@Override
public JsonDeserializer findCollectionDeserializer(CollectionType type, DeserializationConfig config,
DeserializerProvider provider,
BeanDescription beanDesc,
BeanProperty property,
TypeDeserializer elementTypeDeserializer, JsonDeserializer elementDeserializer)
throws JsonMappingException
{
return null;
}
@Override
public JsonDeserializer findEnumDeserializer(Class type, DeserializationConfig config,
BeanDescription beanDesc,
BeanProperty property)
throws JsonMappingException
{
return null;
}
@Override
public JsonDeserializer findMapDeserializer(MapType type, DeserializationConfig config,
DeserializerProvider provider,
BeanDescription beanDesc,
BeanProperty property,
KeyDeserializer keyDeserializer,
TypeDeserializer elementTypeDeserializer, JsonDeserializer elementDeserializer)
throws JsonMappingException
{
return null;
}
@Override
public JsonDeserializer findTreeNodeDeserializer(Class nodeType,
DeserializationConfig config,
BeanProperty property)
throws JsonMappingException
{
return null;
}
@Override
public JsonDeserializer findBeanDeserializer(JavaType type, DeserializationConfig config,
DeserializerProvider provider,
BeanDescription beanDesc,
BeanProperty property)
throws JsonMappingException
{
return null;
}
}
}