Top Description Fields Constructors Methods
tools.jackson.databind.deser

public Class AbstractDeserializer

extends ValueDeserializer<Object>
Class Inheritance
Imports
java.util.*, com.fasterxml.jackson.annotation.ObjectIdGenerator, .ObjectIdGenerators, .ObjectIdResolver, tools.jackson.core.*, tools.jackson.databind.*, tools.jackson.databind.deser.impl.ObjectIdReader, .PropertyBasedObjectIdGenerator, tools.jackson.databind.introspect.AnnotatedMember, .ObjectIdInfo, tools.jackson.databind.jsontype.TypeDeserializer, tools.jackson.databind.type.LogicalType, tools.jackson.databind.util.ClassUtil

Deserializer only used for abstract types used as placeholders during polymorphic type handling deserialization. If so, there is no real deserializer associated with nominal type, just TypeDeserializer; and any calls that do not pass such resolver will result in an error.

Field Summary

Modifier and TypeField and Description
protected final boolean
protected final boolean
protected final boolean
protected final boolean
protected final Map<String, SettableBeanProperty>
protected final JavaType
protected final ObjectIdReader
protected transient Map<String, SettableBeanProperty>

Constructor Summary

AccessConstructor and Description
public
AbstractDeserializer(BeanDeserializerBuilder builder, Map<String, SettableBeanProperty> backRefProps, Map<String, SettableBeanProperty>
Regular properties: currently only needed to support property-annotated Object Id handling with property inclusion (needed for determining type of Object Id to bind)
props
)

protected
protected

Method Summary

Modifier and TypeMethod and Description
protected Object
_deserializeFromObjectId(JsonParser p, DeserializationContext ctxt)

Method called in cases where it looks like we got an Object Id to parse and use as a reference.

protected Object
public static AbstractDeserializer
constructForNonPOJO(BeanDescription.Supplier beanDescRef)

Factory method used when constructing instances for non-POJO types, like java.util.Maps.

public ValueDeserializer<?>
createContextual(DeserializationContext ctxt, BeanProperty property)

Overrides tools.jackson.databind.ValueDeserializer.createContextual.

Method called to see if a different (or differently configured) deserializer is needed to deserialize values of specified property.

public Object
deserialize(JsonParser p, DeserializationContext ctxt)

Implements abstract tools.jackson.databind.ValueDeserializer.deserialize.

Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles.

public Object
deserializeWithType(JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer)

Overrides tools.jackson.databind.ValueDeserializer.deserializeWithType.

Deserialization called when type being deserialized is defined to contain additional type identifier, to allow for correctly instantiating correct subtype.

public SettableBeanProperty
findBackReference(String logicalName)

Overrides tools.jackson.databind.ValueDeserializer.findBackReference.

Method called by BeanDeserializer to resolve back reference part of managed references.

public ObjectIdReader
getObjectIdReader(DeserializationContext ctxt)

Overrides tools.jackson.databind.ValueDeserializer.getObjectIdReader.

Overridden to return true for those instances that are handling value for which Object Identity handling is enabled (either via value type or referring property).

public Class<?>
handledType()

Overrides tools.jackson.databind.ValueDeserializer.handledType.

Method for accessing concrete physical type of values this deserializer produces.

public boolean
isCachable()

Overrides tools.jackson.databind.ValueDeserializer.isCachable.

Method called to see if deserializer instance is cachable and usable for other properties of same type (type for which instance was created).

public LogicalType
logicalType()

Overrides tools.jackson.databind.ValueDeserializer.logicalType.

Method for accessing logical type of values this deserializer produces.

public Boolean
supportsUpdate(DeserializationConfig config)

Overrides tools.jackson.databind.ValueDeserializer.supportsUpdate.

Introspection method that may be called to see whether deserializer supports update of an existing value (aka "merging") or not.

Inherited from tools.jackson.databind.ValueDeserializer:
deserializedeserializeWithTypegetAbsentValuegetDelegateegetEmptyAccessPatterngetEmptyValuegetKnownPropertyNamesgetNullAccessPatterngetNullValuereplaceDelegateeresolveunwrappingDeserializer

Field Detail

_acceptBooleanback to summary
protected final boolean _acceptBoolean
_acceptDoubleback to summary
protected final boolean _acceptDouble
_acceptIntback to summary
protected final boolean _acceptInt
_acceptStringback to summary
protected final boolean _acceptString
_backRefPropertiesback to summary
protected final Map<String, SettableBeanProperty> _backRefProperties
_baseTypeback to summary
protected final JavaType _baseType
_objectIdReaderback to summary
protected final ObjectIdReader _objectIdReader
_propertiesback to summary
protected transient Map<String, SettableBeanProperty> _properties

Constructor Detail

AbstractDeserializerback to summary
public AbstractDeserializer(BeanDeserializerBuilder builder, Map<String, SettableBeanProperty> backRefProps, Map<String, SettableBeanProperty> props)
Parameters
props:Map<String, SettableBeanProperty>

Regular properties: currently only needed to support property-annotated Object Id handling with property inclusion (needed for determining type of Object Id to bind)

AbstractDeserializerback to summary
protected AbstractDeserializer(JavaType baseType)
AbstractDeserializerback to summary
protected AbstractDeserializer(AbstractDeserializer base, ObjectIdReader objectIdReader, Map<String, SettableBeanProperty> props)

Method Detail

_deserializeFromObjectIdback to summary
protected Object _deserializeFromObjectId(JsonParser p, DeserializationContext ctxt) throws JacksonException

Method called in cases where it looks like we got an Object Id to parse and use as a reference.

_deserializeIfNaturalback to summary
protected Object _deserializeIfNatural(JsonParser p, DeserializationContext ctxt) throws JacksonException
constructForNonPOJOback to summary
public static AbstractDeserializer constructForNonPOJO(BeanDescription.Supplier beanDescRef)

Factory method used when constructing instances for non-POJO types, like java.util.Maps.

createContextualback to summary
public ValueDeserializer<?> createContextual(DeserializationContext ctxt, BeanProperty property)

Overrides tools.jackson.databind.ValueDeserializer.createContextual.

Doc from tools.jackson.databind.ValueDeserializer.createContextual.

Method called to see if a different (or differently configured) deserializer is needed to deserialize values of specified property. Note that instance that this method is called on is typically shared one and as a result method should NOT modify this instance but rather construct and return a new instance. This instance should only be returned as-is, in case it is already suitable for use.

Annotations
@Override
deserializeback to summary
public Object deserialize(JsonParser p, DeserializationContext ctxt) throws JacksonException

Implements abstract tools.jackson.databind.ValueDeserializer.deserialize.

Doc from tools.jackson.databind.ValueDeserializer.deserialize.

Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles. Returned instance is to be constructed by method itself.

Pre-condition for this method is that the parser points to the first event that is part of value to deserializer (and which is never JSON 'null' literal, more on this below): for simple types it may be the only value; and for structured types the Object start marker or a FIELD_NAME.

The two possible input conditions for structured types result from polymorphism via fields. In the ordinary case, Jackson calls this method when it has encountered an OBJECT_START, and the method implementation must advance to the next token to see the first field name. If the application configures polymorphism via a field, then the object looks like the following.

      {
          "@class": "class name",
          ...
      }
  
Jackson consumes the two tokens (the @class field name and its value) in order to learn the class and select the deserializer. Thus, the stream is pointing to the FIELD_NAME for the first field after the @class. Thus, if you want your method to work correctly both with and without polymorphism, you must begin your method with:
       if (p.currentToken() == JsonToken.START_OBJECT) {
         p.nextToken();
       }
  
This results in the stream pointing to the field name, so that the two conditions align.

Post-condition is that the parser will point to the last event that is part of deserialized value (or in case deserialization fails, event that was not recognized or usable, which may be the same event as the one it pointed to upon call).

Handling null values (JsonToken.VALUE_NULL)
: Note that this method is never called for the JSON null literal to avoid every deserializer from having to handle null values. Instead, the ValueDeserializer#getNullValue(DeserializationContext) method is called to produce a null value. To influence null handling, custom deserializers should override ValueDeserializer#getNullValue(DeserializationContext) and usually also ValueDeserializer#getNullAccessPattern().

Annotations
@Override
deserializeWithTypeback to summary
public Object deserializeWithType(JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer) throws JacksonException

Overrides tools.jackson.databind.ValueDeserializer.deserializeWithType.

Doc from tools.jackson.databind.ValueDeserializer.deserializeWithType.

Deserialization called when type being deserialized is defined to contain additional type identifier, to allow for correctly instantiating correct subtype. This can be due to annotation on type (or its supertype), or due to global settings without annotations.

Default implementation may work for some types, but ideally subclasses should not rely on current default implementation. Implementation is mostly provided to avoid compilation errors with older code.

Annotations
@Override
findBackReferenceback to summary
public SettableBeanProperty findBackReference(String logicalName)

Overrides tools.jackson.databind.ValueDeserializer.findBackReference.

Method called by BeanDeserializer to resolve back reference part of managed references.

Annotations
@Override
getObjectIdReaderback to summary
public ObjectIdReader getObjectIdReader(DeserializationContext ctxt)

Overrides tools.jackson.databind.ValueDeserializer.getObjectIdReader.

Overridden to return true for those instances that are handling value for which Object Identity handling is enabled (either via value type or referring property).

Annotations
@Override
handledTypeback to summary
public Class<?> handledType()

Overrides tools.jackson.databind.ValueDeserializer.handledType.

Doc from tools.jackson.databind.ValueDeserializer.handledType.

Method for accessing concrete physical type of values this deserializer produces. Note that this information is not guaranteed to be exact -- it may be a more generic (super-type) -- but it should not be incorrect (return a non-related type).

Default implementation will return null, which means almost same same as returning Object.class would; that is, that nothing is known about handled type.

Annotations
@Override
isCachableback to summary
public boolean isCachable()

Overrides tools.jackson.databind.ValueDeserializer.isCachable.

Doc from tools.jackson.databind.ValueDeserializer.isCachable.

Method called to see if deserializer instance is cachable and usable for other properties of same type (type for which instance was created).

Note that cached instances are still contextualized on per-property basis (but note that ValueDeserializer#resolve(DeserializationContext)d just once!) This means that in most cases it is safe to cache instances; however, it only makes sense to cache instances if instantiation is expensive, or if instances are heavy-weight.

Default implementation returns false, to indicate that no caching is done.

Annotations
@Override
logicalTypeback to summary
public LogicalType logicalType()

Overrides tools.jackson.databind.ValueDeserializer.logicalType.

Doc from tools.jackson.databind.ValueDeserializer.logicalType.

Method for accessing logical type of values this deserializer produces. Typically used for further configuring handling of values, for example, to find which coercions are legal.

Annotations
@Override
supportsUpdateback to summary
public Boolean supportsUpdate(DeserializationConfig config)

Overrides tools.jackson.databind.ValueDeserializer.supportsUpdate.

Doc from tools.jackson.databind.ValueDeserializer.supportsUpdate.

Introspection method that may be called to see whether deserializer supports update of an existing value (aka "merging") or not. Return value should either be Boolean#FALSE if update is not supported at all (immutable values); Boolean#TRUE if update should usually work (regular POJOs, for example), or null if this is either not known, or may sometimes work.

Information gathered is typically used to either prevent merging update for property (either by skipping, if based on global defaults; or by exception during deserializer construction if explicit attempt made) if Boolean#FALSE returned, or inclusion if Boolean#TRUE is specified. If "unknown" case (null returned) behavior is to exclude property if global defaults used; or to allow if explicit per-type or property merging is defined.

Default implementation returns null to allow explicit per-type or per-property attempts.

Annotations
@Override