Class UntypedObjectDeserializer
- java.lang.Object
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- com.fasterxml.jackson.databind.JsonDeserializer<T>
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- com.fasterxml.jackson.databind.deser.std.StdDeserializer<java.lang.Object>
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- com.fasterxml.jackson.databind.deser.std.UntypedObjectDeserializer
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- All Implemented Interfaces:
ContextualDeserializer
,NullValueProvider
,ResolvableDeserializer
,ValueInstantiator.Gettable
,java.io.Serializable
public class UntypedObjectDeserializer extends StdDeserializer<java.lang.Object> implements ResolvableDeserializer, ContextualDeserializer
Deserializer implementation that is used if it is necessary to bind content of "unknown" type; something declared as basicObject
(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 JavaList
s (or, if configured, Object[]), JSON objects toMap
s, numbers toNumber
s, booleans toBoolean
s and strings toString
(and nulls to nulls).- See Also:
- Serialized Form
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
UntypedObjectDeserializer.Vanilla
Streamlined version ofUntypedObjectDeserializer
that has fewer checks and is only used when no custom deserializer overrides are applied.-
Nested classes/interfaces inherited from class com.fasterxml.jackson.databind.JsonDeserializer
JsonDeserializer.None
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Constructor Summary
Constructors Constructor Description UntypedObjectDeserializer()
Deprecated.Since 2.6 use variant takes type argumentsUntypedObjectDeserializer(UntypedObjectDeserializer base, JsonDeserializer<?> mapDeser, JsonDeserializer<?> listDeser, JsonDeserializer<?> stringDeser, JsonDeserializer<?> numberDeser)
UntypedObjectDeserializer(JavaType listType, JavaType mapType)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description 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.java.lang.Object
deserialize(JsonParser p, DeserializationContext ctxt)
Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles.java.lang.Object
deserialize(JsonParser p, DeserializationContext ctxt, java.lang.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.java.lang.Object
deserializeWithType(JsonParser p, 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).LogicalType
logicalType()
Method for accessing logical type of values this deserializer produces.void
resolve(DeserializationContext ctxt)
We need to implement this method to properly find things to delegate to: it cannot be done earlier since delegated deserializers almost certainly require access to this instance (at least "List" and "Map" ones)java.lang.Boolean
supportsUpdate(DeserializationConfig config)
Introspection method that may be called to see whether deserializer supports update of an existing value (aka "merging") or not.-
Methods inherited from class com.fasterxml.jackson.databind.deser.std.StdDeserializer
getValueClass, getValueInstantiator, getValueType, getValueType, handledType
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Methods inherited from class com.fasterxml.jackson.databind.JsonDeserializer
deserializeWithType, findBackReference, getAbsentValue, getDelegatee, getEmptyAccessPattern, getEmptyValue, getEmptyValue, getKnownPropertyNames, getNullAccessPattern, getNullValue, getNullValue, getObjectIdReader, replaceDelegatee, unwrappingDeserializer
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Constructor Detail
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UntypedObjectDeserializer
@Deprecated public UntypedObjectDeserializer()
Deprecated.Since 2.6 use variant takes type arguments
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UntypedObjectDeserializer
public UntypedObjectDeserializer(UntypedObjectDeserializer base, JsonDeserializer<?> mapDeser, JsonDeserializer<?> listDeser, JsonDeserializer<?> stringDeser, JsonDeserializer<?> numberDeser)
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Method Detail
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resolve
public void resolve(DeserializationContext ctxt) throws JsonMappingException
We need to implement this method to properly find things to delegate to: it cannot be done earlier since delegated deserializers almost certainly require access to this instance (at least "List" and "Map" ones)- Specified by:
resolve
in interfaceResolvableDeserializer
- Parameters:
ctxt
- Context to use for accessing configuration, resolving secondary deserializers- Throws:
JsonMappingException
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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 interfaceContextualDeserializer
- Parameters:
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)- Returns:
- Deserializer to use for deserializing values of specified property; may be this instance or a new instance.
- Throws:
JsonMappingException
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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 classJsonDeserializer<java.lang.Object>
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logicalType
public LogicalType logicalType()
Description copied from class:JsonDeserializer
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.- Overrides:
logicalType
in classJsonDeserializer<java.lang.Object>
- Returns:
- Logical type of values this deserializer produces, if known;
null
if not
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supportsUpdate
public java.lang.Boolean supportsUpdate(DeserializationConfig config)
Description copied from class:JsonDeserializer
Introspection method that may be called to see whether deserializer supports update of an existing value (aka "merging") or not. Return value should either beBoolean.FALSE
if update is not supported at all (immutable values);Boolean.TRUE
if update should usually work (regular POJOs, for example), ornull
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 ifBoolean.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.- Overrides:
supportsUpdate
in classJsonDeserializer<java.lang.Object>
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deserialize
public java.lang.Object deserialize(JsonParser p, DeserializationContext ctxt) throws java.io.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 (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).
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 classJsonDeserializer<java.lang.Object>
- Parameters:
p
- Parsed used for reading JSON contentctxt
- Context that can be used to access information about this deserialization activity.- Returns:
- Deserialized value
- Throws:
java.io.IOException
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deserializeWithType
public java.lang.Object deserializeWithType(JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer) throws java.io.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 classStdDeserializer<java.lang.Object>
typeDeserializer
- Deserializer to use for handling type information- Throws:
java.io.IOException
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deserialize
public java.lang.Object deserialize(JsonParser p, DeserializationContext ctxt, java.lang.Object intoValue) throws java.io.IOException
Description copied from class:JsonDeserializer
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. 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)- Overrides:
deserialize
in classJsonDeserializer<java.lang.Object>
- Throws:
java.io.IOException
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