T
- Target type to convert to, from delegate typepublic class StdDelegatingDeserializer<T> extends StdDeserializer<T> implements ContextualDeserializer, ResolvableDeserializer
Converter
into desired target type.
Common delegate types to use are Map
and JsonNode
.
Note that although types (delegate, target) may be related, they must not be same; trying to do this will result in an exception.
Since 2.5 There is StdNodeBasedDeserializer
that is a simplified version
for cases where intermediate type is JsonNode
StdNodeBasedDeserializer
,
Converter
,
Serialized FormJsonDeserializer.None
Modifier and Type | Field and Description |
---|---|
protected Converter<Object,T> |
_converter
Converter that was used for creating
_delegateDeserializer . |
protected JsonDeserializer<Object> |
_delegateDeserializer
Underlying serializer for type
T . |
protected JavaType |
_delegateType
Fully resolved delegate type, with generic information if any available.
|
_valueClass, F_MASK_ACCEPT_ARRAYS, F_MASK_INT_COERCIONS
Modifier | Constructor and Description |
---|---|
|
StdDelegatingDeserializer(Converter<?,T> converter) |
|
StdDelegatingDeserializer(Converter<Object,T> converter,
JavaType delegateType,
JsonDeserializer<?> delegateDeserializer) |
protected |
StdDelegatingDeserializer(StdDelegatingDeserializer<T> src) |
Modifier and Type | Method and Description |
---|---|
protected Object |
_handleIncompatibleUpdateValue(JsonParser p,
DeserializationContext ctxt,
Object intoValue)
Overridable handler method called when
deserialize(JsonParser, DeserializationContext, Object)
has been called with a value that is not compatible with delegate value. |
protected T |
convertValue(Object delegateValue)
Method called to convert from "delegate value" (which was deserialized
from JSON using standard Jackson deserializer for delegate type)
into desired target type.
|
JsonDeserializer<?> |
createContextual(DeserializationContext ctxt,
BeanProperty property)
Method called to see if a different (or differently configured) deserializer
is needed to deserialize values of specified property.
|
T |
deserialize(JsonParser p,
DeserializationContext ctxt)
Method that can be called to ask implementation to deserialize
JSON content into the value type this serializer handles.
|
T |
deserialize(JsonParser p,
DeserializationContext ctxt,
Object intoValue)
Alternate deserialization method (compared to the most commonly
used,
JsonDeserializer.deserialize(JsonParser, DeserializationContext) ),
which takes in initialized value instance, to be
configured and/or populated by deserializer. |
Object |
deserializeWithType(JsonParser p,
DeserializationContext ctxt,
TypeDeserializer typeDeserializer)
Base implementation that does not assume specific type
inclusion mechanism.
|
JsonDeserializer<?> |
getDelegatee()
Accessor that can be used to determine if this deserializer uses
another deserializer for actual deserialization, by delegating
calls.
|
Class<?> |
handledType()
Method for accessing type of values this deserializer produces.
|
void |
resolve(DeserializationContext ctxt)
Method called after deserializer instance has been constructed
(and registered as necessary by provider objects),
but before it has returned it to the caller.
|
Boolean |
supportsUpdate(DeserializationConfig config)
Introspection method that may be called to see whether deserializer supports
update of an existing value (aka "merging") or not.
|
protected StdDelegatingDeserializer<T> |
withDelegate(Converter<Object,T> converter,
JavaType delegateType,
JsonDeserializer<?> delegateDeserializer)
Method used for creating resolved contextual instances.
|
_byteOverflow, _coercedTypeDesc, _coerceEmptyString, _coerceIntegral, _coerceNullToken, _coerceTextualNull, _deserializeFromArray, _deserializeFromEmpty, _deserializeWrappedValue, _failDoubleToIntCoercion, _findNullProvider, _hasTextualNull, _intOverflow, _isEmptyOrTextualNull, _isIntNumber, _isNaN, _isNegInf, _isPosInf, _neitherNull, _nonNullNumber, _parseBooleanFromInt, _parseBooleanPrimitive, _parseBytePrimitive, _parseDate, _parseDate, _parseDateFromArray, _parseDoublePrimitive, _parseDoublePrimitive, _parseFloatPrimitive, _parseFloatPrimitive, _parseIntPrimitive, _parseIntPrimitive, _parseLongPrimitive, _parseLongPrimitive, _parseShortPrimitive, _parseString, _reportFailedNullCoerce, _shortOverflow, _verifyEndArrayForSingle, _verifyNullForPrimitive, _verifyNullForPrimitiveCoercion, _verifyNullForScalarCoercion, _verifyNumberForScalarCoercion, _verifyStringForScalarCoercion, findContentNullProvider, findContentNullStyle, findConvertingContentDeserializer, findDeserializer, findFormatFeature, findFormatOverrides, findValueNullProvider, getValueClass, getValueType, handleMissingEndArrayForSingle, handleUnknownProperty, isDefaultDeserializer, isDefaultKeyDeserializer, parseDouble
findBackReference, getEmptyAccessPattern, getEmptyValue, getEmptyValue, getKnownPropertyNames, getNullAccessPattern, getNullValue, getNullValue, getObjectIdReader, isCachable, replaceDelegatee, unwrappingDeserializer
protected final Converter<Object,T> _converter
_delegateDeserializer
.protected final JavaType _delegateType
protected final JsonDeserializer<Object> _delegateDeserializer
T
.public StdDelegatingDeserializer(Converter<Object,T> converter, JavaType delegateType, JsonDeserializer<?> delegateDeserializer)
protected StdDelegatingDeserializer(StdDelegatingDeserializer<T> src)
protected StdDelegatingDeserializer<T> withDelegate(Converter<Object,T> converter, JavaType delegateType, JsonDeserializer<?> delegateDeserializer)
public void resolve(DeserializationContext ctxt) throws JsonMappingException
ResolvableDeserializer
resolve
in interface ResolvableDeserializer
ctxt
- Context to use for accessing configuration, resolving
secondary deserializersJsonMappingException
public JsonDeserializer<?> createContextual(DeserializationContext ctxt, BeanProperty property) throws JsonMappingException
ContextualDeserializer
createContextual
in interface ContextualDeserializer
ctxt
- Deserialization context to access configuration, additional
deserializers that may be needed by this deserializerproperty
- 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 cannot provide it and
null is passed instead (in which case impls usually pass 'this' deserializer as is)JsonMappingException
public JsonDeserializer<?> getDelegatee()
JsonDeserializer
getDelegatee
in class JsonDeserializer<T>
public Class<?> handledType()
JsonDeserializer
Default implementation will return null, which means almost same
same as returning Object.class
would; that is, that
nothing is known about handled type.
handledType
in class StdDeserializer<T>
public Boolean supportsUpdate(DeserializationConfig config)
JsonDeserializer
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
deserialization 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.
supportsUpdate
in class JsonDeserializer<T>
public T deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
JsonDeserializer
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.getCurrentToken() == 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).
Note that this method is never called for JSON null literal, and thus deserializers need (and should) not check for it.
deserialize
in class JsonDeserializer<T>
p
- Parsed used for reading JSON contentctxt
- Context that can be used to access information about
this deserialization activity.IOException
public Object deserializeWithType(JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer) throws IOException
StdDeserializer
deserializeWithType
in class StdDeserializer<T>
typeDeserializer
- Deserializer to use for handling type informationIOException
public T deserialize(JsonParser p, DeserializationContext ctxt, Object intoValue) throws IOException
JsonDeserializer
JsonDeserializer.deserialize(JsonParser, DeserializationContext)
),
which takes in initialized value instance, to be
configured and/or populated by deserializer.
Method is not necessarily used (or supported) by all types
(it will not work for immutable types, for obvious reasons):
most commonly it is used for Collections and Maps.
It may be used both with "updating readers" (for POJOs) and
when Collections and Maps use "getter as setter".
Default implementation just throws
UnsupportedOperationException
, to indicate that types
that do not explicitly add support do not necessarily support
update-existing-value operation (esp. immutable types)
deserialize
in class JsonDeserializer<T>
IOException
protected Object _handleIncompatibleUpdateValue(JsonParser p, DeserializationContext ctxt, Object intoValue) throws IOException
deserialize(JsonParser, DeserializationContext, Object)
has been called with a value that is not compatible with delegate value.
Since no conversion are expected for such "updateValue" case, this is normally not
an operation that can be permitted, and the default behavior is to throw exception.
Sub-classes may choose to try alternative approach if they have more information on
exact usage and constraints.IOException
protected T convertValue(Object delegateValue)
The default implementation uses configured Converter
to do
conversion.
delegateValue
- Copyright © 2018 JBoss by Red Hat. All rights reserved.