com.fasterxml.jackson.databind.deser

Interface Deserializers

All Known Implementing Classes:

CoreXMLDeserializers, Deserializers.Base, SimpleDeserializers

public interface Deserializers

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 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.

It is strongly recommended that implementations always extend Deserializers.Base and NOT just implement Deserializers.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Deserializers.Base Basic Deserializers implementation that implements all methods but provides no deserializers.

Method Summary

Modifier and Type	Method and Description
JsonDeserializer<?>	findArrayDeserializer(ArrayType type, DeserializationConfig config, BeanDescription beanDesc, TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer) Method called to locate serializer for specified array type.
JsonDeserializer<?>	findBeanDeserializer(JavaType type, DeserializationConfig config, BeanDescription beanDesc) Method called to locate deserializer for specified value type which does not belong to any other category (not an Enum, Collection, Map, Array, reference value or tree node)
JsonDeserializer<?>	findCollectionDeserializer(CollectionType type, DeserializationConfig config, BeanDescription beanDesc, TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer) Method called to locate serializer for specified Collection (List, Set etc) type.
JsonDeserializer<?>	findCollectionLikeDeserializer(CollectionLikeType type, DeserializationConfig config, BeanDescription beanDesc, TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer) Method called to locate serializer for specified "Collection-like" type (one that acts like Collection but does not implement it).
JsonDeserializer<?>	findEnumDeserializer(Class<?> type, DeserializationConfig config, BeanDescription beanDesc) Method called to locate deserializer for specified Enum type.
JsonDeserializer<?>	findMapDeserializer(MapType type, DeserializationConfig config, BeanDescription beanDesc, KeyDeserializer keyDeserializer, TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer) Method called to locate deserializer for specified Map type.
JsonDeserializer<?>	findMapLikeDeserializer(MapLikeType type, DeserializationConfig config, BeanDescription beanDesc, KeyDeserializer keyDeserializer, TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer) Method called to locate serializer for specified "Map-like" type (one that acts like Map but does not implement it).
JsonDeserializer<?>	findReferenceDeserializer(ReferenceType refType, DeserializationConfig config, BeanDescription beanDesc, TypeDeserializer contentTypeDeserializer, JsonDeserializer<?> contentDeserializer) Method called to locate deserializer for value that is of referential type,
JsonDeserializer<?>	findTreeNodeDeserializer(Class<? extends JsonNode> nodeType, DeserializationConfig config, BeanDescription beanDesc) Method called to locate deserializer for specified JSON tree node type.
default boolean	hasDeserializerFor(DeserializationConfig config, Class<?> valueType) Method that may be called to check whether this deserializer provider would provide deserializer for values of given type, without attempting to construct (and possibly fail in some cases) actual deserializer.

Method Detail

findEnumDeserializer

JsonDeserializer<?> findEnumDeserializer(Class<?> type,
                                         DeserializationConfig config,
                                         BeanDescription beanDesc)
                                  throws JsonMappingException

Method called to locate deserializer for specified Enum type.

Parameters:

type - Type of Enum instances to deserialize

config - Configuration in effect

beanDesc - Definition of the enumeration type that contains class annotations and other information typically needed for building deserializers

Returns:

Deserializer to use for the type; or null if this provider does not know how to construct it

Throws:

JsonMappingException

findTreeNodeDeserializer

JsonDeserializer<?> findTreeNodeDeserializer(Class<? extends JsonNode> nodeType,
                                             DeserializationConfig config,
                                             BeanDescription beanDesc)
                                      throws JsonMappingException

Method called to locate deserializer for specified JSON tree node type.

Parameters:

nodeType - Specific type of JSON tree nodes to deserialize (subtype of JsonNode)

config - Configuration in effect

Returns:

Deserializer to use for the type; or null if this provider does not know how to construct it

Throws:

JsonMappingException

findBeanDeserializer

JsonDeserializer<?> findBeanDeserializer(JavaType type,
                                         DeserializationConfig config,
                                         BeanDescription beanDesc)
                                  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, reference value or tree node)

Parameters:

type - Bean type to deserialize

config - Configuration in effect

beanDesc - Definition of the enumeration type that contains class annotations and other information typically needed for building deserializers

Returns:

Deserializer to use for the type; or null if this provider does not know how to construct it

Throws:

JsonMappingException

findReferenceDeserializer

JsonDeserializer<?> findReferenceDeserializer(ReferenceType refType,
                                              DeserializationConfig config,
                                              BeanDescription beanDesc,
                                              TypeDeserializer contentTypeDeserializer,
                                              JsonDeserializer<?> contentDeserializer)
                                       throws JsonMappingException

Method called to locate deserializer for value that is of referential type,

Parameters:

refType - Specific referential type to deserialize

config - Configuration in effect

beanDesc - Definition of the reference type that contains class annotations and other information typically needed for building deserializers

contentTypeDeserializer - Possible type deserializer for referenced value

contentDeserializer - Value deserializer to use for referenced value, if indicated by property annotation

Returns:

Deserializer to use for the type; or null if this provider does not know how to construct it

Throws:

JsonMappingException

Since:

2.7

findArrayDeserializer

JsonDeserializer<?> findArrayDeserializer(ArrayType type,
                                          DeserializationConfig config,
                                          BeanDescription beanDesc,
                                          TypeDeserializer elementTypeDeserializer,
                                          JsonDeserializer<?> elementDeserializer)
                                   throws JsonMappingException

Method called to locate serializer 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).

Parameters:

type - Type of array instances to deserialize

config - Configuration in effect

beanDesc - Definition of the enumeration type that contains class annotations and other information typically needed for building deserializers

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.

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 ResolvableDeserializer callback)

Returns:

Deserializer to use for the type; or null if this provider does not know how to construct it

Throws:

JsonMappingException

findCollectionDeserializer

JsonDeserializer<?> findCollectionDeserializer(CollectionType type,
                                               DeserializationConfig config,
                                               BeanDescription beanDesc,
                                               TypeDeserializer elementTypeDeserializer,
                                               JsonDeserializer<?> elementDeserializer)
                                        throws JsonMappingException

Method called to locate serializer for specified 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).

Parameters:

type - Type of collection instances to deserialize

config - Configuration in effect

beanDesc - Definition of the enumeration type that contains class annotations and other information typically needed for building deserializers

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.

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 ResolvableDeserializer callback)

Returns:

Deserializer to use for the type; or null if this provider does not know how to construct it

Throws:

JsonMappingException

findCollectionLikeDeserializer

JsonDeserializer<?> findCollectionLikeDeserializer(CollectionLikeType type,
                                                   DeserializationConfig config,
                                                   BeanDescription beanDesc,
                                                   TypeDeserializer elementTypeDeserializer,
                                                   JsonDeserializer<?> elementDeserializer)
                                            throws JsonMappingException

Method called to locate serializer for specified "Collection-like" type (one that acts like Collection but does not implement it).

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).

Parameters:

type - Type of instances to deserialize

config - Configuration in effect

beanDesc - Definition of the enumeration type that contains class annotations and other information typically needed for building deserializers

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.

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 ResolvableDeserializer callback)

Returns:

Deserializer to use for the type; or null if this provider does not know how to construct it

Throws:

JsonMappingException

findMapDeserializer

JsonDeserializer<?> findMapDeserializer(MapType type,
                                        DeserializationConfig config,
                                        BeanDescription beanDesc,
                                        KeyDeserializer keyDeserializer,
                                        TypeDeserializer elementTypeDeserializer,
                                        JsonDeserializer<?> elementDeserializer)
                                 throws JsonMappingException

Method called to locate deserializer for specified 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 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 later during resolution (using ResolvableDeserializer.resolve(com.fasterxml.jackson.databind.DeserializationContext)).

Parameters:

type - Type of Map instances to deserialize

config - Configuration in effect

beanDesc - Definition of the enumeration type that contains class annotations and other information typically needed for building deserializers

keyDeserializer - Key deserializer use, if it is defined via annotations or other configuration; null if default key deserializer for key type can be used.

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.

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 ResolvableDeserializer callback)

Returns:

Deserializer to use for the type; or null if this provider does not know how to construct it

Throws:

JsonMappingException

findMapLikeDeserializer

JsonDeserializer<?> findMapLikeDeserializer(MapLikeType type,
                                            DeserializationConfig config,
                                            BeanDescription beanDesc,
                                            KeyDeserializer keyDeserializer,
                                            TypeDeserializer elementTypeDeserializer,
                                            JsonDeserializer<?> elementDeserializer)
                                     throws JsonMappingException

Method called to locate serializer for specified "Map-like" type (one that acts like Map but does not implement it).

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 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 later during resolution (using ResolvableDeserializer.resolve(com.fasterxml.jackson.databind.DeserializationContext)).

Parameters:

type - Type of Map instances to deserialize

config - Configuration in effect

beanDesc - Definition of the enumeration type that contains class annotations and other information typically needed for building deserializers

keyDeserializer - Key deserializer use, if it is defined via annotations or other configuration; null if default key deserializer for key type can be used.

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.

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 ResolvableDeserializer callback)

Returns:

Deserializer to use for the type; or null if this provider does not know how to construct it

Throws:

JsonMappingException

hasDeserializerFor

default boolean hasDeserializerFor(DeserializationConfig config,
                                   Class<?> valueType)

Method that may be called to check whether this deserializer provider would provide deserializer for values of given type, without attempting to construct (and possibly fail in some cases) actual deserializer. Mostly needed to support validation of polymorphic type ids.

Note: implementations should take care NOT to claim supporting types that they do not recognize as this could to incorrect assumption of safe support by caller.

Method added in Jackson 2.13 now that Java 8 default implementations are available for use with interface definitions.

Since:

2.13