com.fasterxml.jackson.databind.deser

Interface NullValueProvider

All Known Implementing Classes:

AbstractDeserializer, ArrayBlockingQueueDeserializer, AtomicBooleanDeserializer, AtomicIntegerDeserializer, AtomicLongDeserializer, AtomicReferenceDeserializer, BeanAsArrayBuilderDeserializer, BeanAsArrayDeserializer, BeanDeserializer, BeanDeserializerBase, BuilderBasedDeserializer, ByteBufferDeserializer, CollectionDeserializer, ContainerDeserializerBase, CoreXMLDeserializers.Std, DateDeserializers.CalendarDeserializer, DateDeserializers.DateBasedDeserializer, DateDeserializers.DateDeserializer, DateDeserializers.SqlDateDeserializer, DateDeserializers.TimestampDeserializer, DelegatingDeserializer, DOMDeserializer, DOMDeserializer.DocumentDeserializer, DOMDeserializer.NodeDeserializer, EnumDeserializer, EnumMapDeserializer, EnumSetDeserializer, ErrorThrowingDeserializer, FailingDeserializer, FromStringDeserializer, FromStringDeserializer.Std, JsonDeserializer, JsonDeserializer.None, JsonNodeDeserializer, MapDeserializer, MapEntryDeserializer, NioPathDeserializer, NullifyingDeserializer, NullsAsEmptyProvider, NullsConstantProvider, NullsFailProvider, NumberDeserializers.BigDecimalDeserializer, NumberDeserializers.BigIntegerDeserializer, NumberDeserializers.BooleanDeserializer, NumberDeserializers.ByteDeserializer, NumberDeserializers.CharacterDeserializer, NumberDeserializers.DoubleDeserializer, NumberDeserializers.FloatDeserializer, NumberDeserializers.IntegerDeserializer, NumberDeserializers.LongDeserializer, NumberDeserializers.NumberDeserializer, NumberDeserializers.PrimitiveOrWrapperDeserializer, NumberDeserializers.ShortDeserializer, ObjectArrayDeserializer, PrimitiveArrayDeserializers, ReferenceTypeDeserializer, StackTraceElementDeserializer, StdDelegatingDeserializer, StdDeserializer, StdNodeBasedDeserializer, StdScalarDeserializer, StringArrayDeserializer, StringCollectionDeserializer, StringDeserializer, ThrowableDeserializer, TokenBufferDeserializer, TypeWrappedDeserializer, UnsupportedTypeDeserializer, UntypedObjectDeserializer, UntypedObjectDeserializer.Vanilla, UUIDDeserializer

public interface NullValueProvider

Helper interface implemented by classes that are to be used as null providers during deserialization. Most importantly implemented by JsonDeserializer (as a mix-in interface), but also by converters used to support more configurable null replacement.

Since:

2.9

Method Summary

Modifier and Type	Method and Description
default Object	getAbsentValue(DeserializationContext ctxt) Method called to determine placeholder value to be used for cases where no value was obtained from input but we must pass a value nonetheless: the common case is that of Creator methods requiring passing a value for every parameter.
AccessPattern	getNullAccessPattern() Accessor that may be used to determine if and when provider must be called to access null replacement value.
Object	getNullValue(DeserializationContext ctxt) Method called to possibly convert incoming `null` token (read via underlying streaming input source) into other value of type accessor supports.

Method Detail

getNullValue

Object getNullValue(DeserializationContext ctxt)
             throws JsonMappingException

Method called to possibly convert incoming `null` token (read via underlying streaming input source) into other value of type accessor supports. May return `null`, or value compatible with type binding.

NOTE: if getNullAccessPattern() returns `ALWAYS_NULL` or `CONSTANT`, this method WILL NOT use provided `ctxt` and it may thus be passed as `null`.

Throws:

JsonMappingException

getNullAccessPattern

AccessPattern getNullAccessPattern()

Accessor that may be used to determine if and when provider must be called to access null replacement value.

getAbsentValue

default Object getAbsentValue(DeserializationContext ctxt)
                       throws JsonMappingException

Method called to determine placeholder value to be used for cases where no value was obtained from input but we must pass a value nonetheless: the common case is that of Creator methods requiring passing a value for every parameter. Usually this is same as getNullValue(com.fasterxml.jackson.databind.DeserializationContext) (which in turn is usually simply Java null), but it can be overridden for specific types: most notable scalar types must use "default" values.

This method needs to be called every time a determination is made.

Default implementation simply calls and returns getNullValue(com.fasterxml.jackson.databind.DeserializationContext).

Throws:

JsonMappingException

Since:

2.13