Module tools.jackson.databind
Package tools.jackson.databind.deser

Interface Deserializers

All Known Implementing Classes:
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 ValueDeserializer 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.

  • Method Details

    • findEnumDeserializer

      default ValueDeserializer<?> findEnumDeserializer(JavaType type, DeserializationConfig config, BeanDescription.Supplier beanDescRef)
      Method called to locate deserializer for specified Enum type.
      Parameters:
      type - Type of Enum instances to deserialize
      config - Configuration in effect
      beanDescRef - 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

    • findTreeNodeDeserializer

      default ValueDeserializer<?> findTreeNodeDeserializer(JavaType nodeType, DeserializationConfig config, BeanDescription.Supplier beanDescRef)
      Method called to locate deserializer for specified JSON tree node type.
      Parameters:
      nodeType - Specific type of JSON tree nodes to deserialize (subtype of TreeNode)
      config - Configuration in effect
      Returns:
      Deserializer to use for the type; or null if this provider does not know how to construct it

    • findBeanDeserializer

      default ValueDeserializer<?> findBeanDeserializer(JavaType type, DeserializationConfig config, BeanDescription.Supplier beanDescRef)
      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
      beanDescRef - 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

    • findReferenceDeserializer

      default ValueDeserializer<?> findReferenceDeserializer(ReferenceType refType, DeserializationConfig config, BeanDescription.Supplier beanDescRef, TypeDeserializer contentTypeDeserializer, ValueDeserializer<?> contentDeserializer)
      Method called to locate deserializer for value that is of referential type,
      Parameters:
      refType - Specific referential type to deserialize
      config - Configuration in effect
      beanDescRef - 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

    • findArrayDeserializer

      default ValueDeserializer<?> findArrayDeserializer(ArrayType type, DeserializationConfig config, BeanDescription.Supplier beanDescRef, TypeDeserializer elementTypeDeserializer, ValueDeserializer<?> elementDeserializer)
      Method called to locate deserializer 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
      beanDescRef - 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 example). May be null, in which case it will need to be resolved by deserializer at a later point.
      Returns:
      Deserializer to use for the type; or null if this provider does not know how to construct it

    • findCollectionDeserializer

      default ValueDeserializer<?> findCollectionDeserializer(CollectionType type, DeserializationConfig config, BeanDescription.Supplier beanDescRef, TypeDeserializer elementTypeDeserializer, ValueDeserializer<?> elementDeserializer)
      Method called to locate deserializer 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
      beanDescRef - 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 example). May be null, in which case it will need to be resolved by deserializer at a later point.
      Returns:
      Deserializer to use for the type; or null if this provider does not know how to construct it

    • findCollectionLikeDeserializer

      default ValueDeserializer<?> findCollectionLikeDeserializer(CollectionLikeType type, DeserializationConfig config, BeanDescription.Supplier beanDescRef, TypeDeserializer elementTypeDeserializer, ValueDeserializer<?> elementDeserializer)
      Method called to locate deserializer 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
      beanDescRef - 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 example). May be null, in which case it will need to be resolved by deserializer at a later point.
      Returns:
      Deserializer to use for the type; or null if this provider does not know how to construct it

    • findMapDeserializer

      default ValueDeserializer<?> findMapDeserializer(MapType type, DeserializationConfig config, BeanDescription.Supplier beanDescRef, KeyDeserializer keyDeserializer, TypeDeserializer elementTypeDeserializer, ValueDeserializer<?> elementDeserializer)
      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 of map serializer constructed here.

      Parameters:
      type - Type of Map instances to deserialize
      config - Configuration in effect
      beanDescRef - 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 example). May be null, in which case it will need to be resolved by deserializer at a later point.
      Returns:
      Deserializer to use for the type; or null if this provider does not know how to construct it

    • findMapLikeDeserializer

      default ValueDeserializer<?> findMapLikeDeserializer(MapLikeType type, DeserializationConfig config, BeanDescription.Supplier beanDescRef, KeyDeserializer keyDeserializer, TypeDeserializer elementTypeDeserializer, ValueDeserializer<?> elementDeserializer)
      Method called to locate deserializer 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, by deserializer constructed here.

      Parameters:
      type - Type of Map instances to deserialize
      config - Configuration in effect
      beanDescRef - 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 example). May be null, in which case it will need to be resolved by deserializer at a later point.
      Returns:
      Deserializer to use for the type; or null if this provider does not know how to construct it

    • hasDeserializerFor

      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.

      Since:
      3.0