com.fasterxml.jackson.databind.deser.std

Class UntypedObjectDeserializer

java.lang.Object

com.fasterxml.jackson.databind.JsonDeserializer<T>

com.fasterxml.jackson.databind.deser.std.StdDeserializer<Object>

com.fasterxml.jackson.databind.deser.std.UntypedObjectDeserializer

All Implemented Interfaces:

ContextualDeserializer, ResolvableDeserializer, Serializable

public class UntypedObjectDeserializer
extends StdDeserializer<Object>
implements ResolvableDeserializer, ContextualDeserializer

Deserializer implementation that is used if it is necessary to bind content of "unknown" type; something declared as basic Object (either explicitly, or due to type erasure). If so, "natural" mapping is used to convert JSON values to their natural Java object matches: JSON arrays to Java Lists (or, if configured, Object[]), JSON objects to Maps, numbers to Numbers, booleans to Booleans and strings to String (and nulls to nulls).

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	UntypedObjectDeserializer.Vanilla

Nested classes/interfaces inherited from class com.fasterxml.jackson.databind.JsonDeserializer

JsonDeserializer.None

Field Summary

Fields

Modifier and Type	Field and Description
protected JsonDeserializer<Object>	_listDeserializer
protected JsonDeserializer<Object>	_mapDeserializer
protected JsonDeserializer<Object>	_numberDeserializer
protected JsonDeserializer<Object>	_stringDeserializer
static UntypedObjectDeserializer	instance Deprecated. Since 2.3, construct a new instance, needs to be resolved
protected static Object[]	NO_OBJECTS

Fields inherited from class com.fasterxml.jackson.databind.deser.std.StdDeserializer

_valueClass

Constructor Summary

Constructors

Constructor and Description
UntypedObjectDeserializer()
UntypedObjectDeserializer(UntypedObjectDeserializer base, JsonDeserializer<?> mapDeser, JsonDeserializer<?> listDeser, JsonDeserializer<?> stringDeser, JsonDeserializer<?> numberDeser)

Method Summary

Modifier and Type	Method and Description
protected JsonDeserializer<Object>	_findCustomDeser(DeserializationContext ctxt, JavaType type)
protected JsonDeserializer<?>	_withResolved(JsonDeserializer<?> mapDeser, JsonDeserializer<?> listDeser, JsonDeserializer<?> stringDeser, JsonDeserializer<?> numberDeser)
JsonDeserializer<?>	createContextual(DeserializationContext ctxt, BeanProperty property) We only use contextualization for optimizing the case where no customization occurred; if so, can slip in a more streamlined version.
Object	deserialize(JsonParser jp, DeserializationContext ctxt) Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles.
Object	deserializeWithType(JsonParser jp, DeserializationContext ctxt, TypeDeserializer typeDeserializer) Base implementation that does not assume specific type inclusion mechanism.
boolean	isCachable() Method called to see if deserializer instance is cachable and usable for other properties of same type (type for which instance was created).
protected Object	mapArray(JsonParser jp, DeserializationContext ctxt) Method called to map a JSON Array into a Java value.
protected Object[]	mapArrayToArray(JsonParser jp, DeserializationContext ctxt) Method called to map a JSON Array into a Java Object array (Object[]).
protected Object	mapObject(JsonParser jp, DeserializationContext ctxt) Method called to map a JSON Object into a Java value.
void	resolve(DeserializationContext ctxt) We need to implement this method to properly find things to delegate to: it can not be done earlier since delegated deserializers almost certainly require access to this instance (at least "List" and "Map" ones)

Methods inherited from class com.fasterxml.jackson.databind.deser.std.StdDeserializer

_deserializeFromEmpty, _hasTextualNull, _isNaN, _isNegInf, _isPosInf, _parseBoolean, _parseBooleanFromNumber, _parseBooleanPrimitive, _parseByte, _parseDate, _parseDouble, _parseDoublePrimitive, _parseFloat, _parseFloatPrimitive, _parseInteger, _parseIntPrimitive, _parseLong, _parseLongPrimitive, _parseShort, _parseShortPrimitive, _parseString, findConvertingContentDeserializer, findDeserializer, getValueClass, getValueType, handledType, handleUnknownProperty, isDefaultDeserializer, isDefaultKeyDeserializer, parseDouble

Methods inherited from class com.fasterxml.jackson.databind.JsonDeserializer

deserialize, findBackReference, getDelegatee, getEmptyValue, getKnownPropertyNames, getNullValue, getObjectIdReader, replaceDelegatee, unwrappingDeserializer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NO_OBJECTS

protected static final Object[] NO_OBJECTS

instance

@Deprecated
public static final UntypedObjectDeserializer instance

Deprecated. Since 2.3, construct a new instance, needs to be resolved

_mapDeserializer

protected JsonDeserializer<Object> _mapDeserializer

_listDeserializer

protected JsonDeserializer<Object> _listDeserializer

_stringDeserializer

protected JsonDeserializer<Object> _stringDeserializer

_numberDeserializer

protected JsonDeserializer<Object> _numberDeserializer

Constructor Detail

UntypedObjectDeserializer

public UntypedObjectDeserializer()

UntypedObjectDeserializer

public UntypedObjectDeserializer(UntypedObjectDeserializer base,
                                 JsonDeserializer<?> mapDeser,
                                 JsonDeserializer<?> listDeser,
                                 JsonDeserializer<?> stringDeser,
                                 JsonDeserializer<?> numberDeser)

Method Detail

resolve

public void resolve(DeserializationContext ctxt)
             throws JsonMappingException

We need to implement this method to properly find things to delegate to: it can not be done earlier since delegated deserializers almost certainly require access to this instance (at least "List" and "Map" ones)

Specified by:

resolve in interface ResolvableDeserializer

Parameters:

ctxt - Context to use for accessing configuration, resolving secondary deserializers

Throws:

JsonMappingException

_findCustomDeser

protected JsonDeserializer<Object> _findCustomDeser(DeserializationContext ctxt,
                                                    JavaType type)
                                             throws JsonMappingException

Throws:

JsonMappingException

createContextual

public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
                                            BeanProperty property)
                                     throws JsonMappingException

We only use contextualization for optimizing the case where no customization occurred; if so, can slip in a more streamlined version.

Specified by:

createContextual in interface ContextualDeserializer

Parameters:

ctxt - Deserialization context to access configuration, additional deserializers that may be needed by this deserializer

property - Method, field or constructor parameter that represents the property (and is used to assign deserialized value). Should be available; but there may be cases where caller can not provide it and null is passed instead (in which case impls usually pass 'this' deserializer as is)

Returns:

Deserializer to use for deserializing values of specified property; may be this instance or a new instance.

Throws:

JsonMappingException

_withResolved

protected JsonDeserializer<?> _withResolved(JsonDeserializer<?> mapDeser,
                                            JsonDeserializer<?> listDeser,
                                            JsonDeserializer<?> stringDeser,
                                            JsonDeserializer<?> numberDeser)

isCachable

public boolean isCachable()

Description copied from class: JsonDeserializer

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 resolved on per-property basis, if instance implements ResolvableDeserializer: cached instance is just as the base. 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.

Overrides:

isCachable in class JsonDeserializer<Object>

deserialize

public Object deserialize(JsonParser jp,
                          DeserializationContext ctxt)
                   throws IOException

Description copied from class: JsonDeserializer

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 (jp.getCurrentToken() == JsonToken.START_OBJECT) {
         jp.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).

Note that this method is never called for JSON null literal, and thus deserializers need (and should) not check for it.

Specified by:

deserialize in class JsonDeserializer<Object>

Parameters:

jp - Parsed used for reading JSON content

ctxt - Context that can be used to access information about this deserialization activity.

Returns:

Deserialized value

Throws:

IOException

deserializeWithType

public Object deserializeWithType(JsonParser jp,
                                  DeserializationContext ctxt,
                                  TypeDeserializer typeDeserializer)
                           throws IOException

Description copied from class: StdDeserializer

Base implementation that does not assume specific type inclusion mechanism. Sub-classes are expected to override this method if they are to handle type information.

Overrides:

deserializeWithType in class StdDeserializer<Object>

typeDeserializer - Deserializer to use for handling type information

Throws:

IOException

mapArray

protected Object mapArray(JsonParser jp,
                          DeserializationContext ctxt)
                   throws IOException

Method called to map a JSON Array into a Java value.

Throws:

IOException

mapObject

protected Object mapObject(JsonParser jp,
                           DeserializationContext ctxt)
                    throws IOException

Method called to map a JSON Object into a Java value.

Throws:

IOException

mapArrayToArray

protected Object[] mapArrayToArray(JsonParser jp,
                                   DeserializationContext ctxt)
                            throws IOException

Method called to map a JSON Array into a Java Object array (Object[]).

Throws:

IOException