com.fasterxml.jackson.databind.deser.std

Class JsonNodeDeserializer

java.lang.Object

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

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

com.fasterxml.jackson.databind.deser.std.JsonNodeDeserializer

All Implemented Interfaces:

NullValueProvider, ValueInstantiator.Gettable, java.io.Serializable

public class JsonNodeDeserializer
extends StdDeserializer<T>

Deserializer that can build instances of JsonNode from any JSON content, using appropriate JsonNode type.

Rewritten in Jackson 2.13 to avoid recursion and allow handling of very deeply nested structures.

See Also:

Serialized Form

Nested Class Summary

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

JsonDeserializer.None

Method Summary

Modifier and Type	Method and Description
JsonNode	deserialize(JsonParser p, DeserializationContext ctxt) Implementation that will produce types of any JSON nodes; not just one deserializer is registered to handle (in case of more specialized handler).
java.lang.Object	deserializeWithType(JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer) Base implementation that does not assume specific type inclusion mechanism.
java.lang.Object	getAbsentValue(DeserializationContext ctxt) Overridden variant to ensure that absent values are NOT coerced into NullNodes, unlike incoming null values.
static JsonDeserializer<? extends JsonNode>	getDeserializer(java.lang.Class<?> nodeClass) Factory method for accessing deserializer for specific node type
JsonNode	getNullValue(DeserializationContext ctxt) Method that can be called to determine value to be used for representing null values (values deserialized when JSON token is JsonToken.VALUE_NULL).
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.
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

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

deserialize, deserializeWithType, findBackReference, getDelegatee, getEmptyAccessPattern, getEmptyValue, getEmptyValue, getKnownPropertyNames, getNullAccessPattern, getNullValue, getObjectIdReader, replaceDelegatee, unwrappingDeserializer

Methods inherited from class java.lang.Object

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

Method Detail

getDeserializer

public static JsonDeserializer<? extends JsonNode> getDeserializer(java.lang.Class<?> nodeClass)

Factory method for accessing deserializer for specific node type

getNullValue

public JsonNode getNullValue(DeserializationContext ctxt)

Description copied from class: JsonDeserializer

Method that can be called to determine value to be used for representing null values (values deserialized when JSON token is JsonToken.VALUE_NULL). Usually this is simply Java null, but for some types (especially primitives) it may be necessary to use non-null values.

This method may be called once, or multiple times, depending on what JsonDeserializer.getNullAccessPattern() returns.

Default implementation simply returns null.

Specified by:

getNullValue in interface NullValueProvider

Overrides:

getNullValue in class JsonDeserializer<JsonNode>

getAbsentValue

public java.lang.Object getAbsentValue(DeserializationContext ctxt)

Overridden variant to ensure that absent values are NOT coerced into NullNodes, unlike incoming null values.

Specified by:

getAbsentValue in interface NullValueProvider

Overrides:

getAbsentValue in class JsonDeserializer<JsonNode>

deserialize

public JsonNode deserialize(JsonParser p,
                            DeserializationContext ctxt)
                     throws java.io.IOException

Implementation that will produce types of any JSON nodes; not just one deserializer is registered to handle (in case of more specialized handler). Overridden by typed sub-classes for more thorough checking

Specified by:

deserialize in class JsonDeserializer<JsonNode>

Parameters:

p - Parsed used for reading JSON content

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

Returns:

Deserialized value

Throws:

java.io.IOException

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 class StdDeserializer<T extends JsonNode>

typeDeserializer - Deserializer to use for handling type information

Throws:

java.io.IOException

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 class JsonDeserializer<T extends JsonNode>

Returns:

Logical type of values this deserializer produces, if known; null if not

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<T extends JsonNode>

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 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 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.

Overrides:

supportsUpdate in class JsonDeserializer<T extends JsonNode>