Package com.fasterxml.jackson.databind.deser.std

Class JsonNodeDeserializer

java.lang.Object
com.fasterxml.jackson.databind.JsonDeserializer<JsonNode>
com.fasterxml.jackson.databind.deser.std.StdDeserializer<JsonNode>
com.fasterxml.jackson.databind.deser.std.JsonNodeDeserializer
All Implemented Interfaces:
ContextualDeserializer, NullValueProvider, ValueInstantiator.Gettable, Serializable
public class JsonNodeDeserializer extends StdDeserializer<JsonNode>
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:

  • Method Details

    • getDeserializer

      public static JsonDeserializer<? extends JsonNode> getDeserializer(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 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 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 - Parser used for reading JSON content
      ctxt - Context that can be used to access information about this deserialization activity.
      Returns:
      Deserialized value
      Throws:
      IOException

    • supportsUpdate

      public 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 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.

    • deserializeWithType

      public Object deserializeWithType(JsonParser p, 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<T extends JsonNode>
      Parameters:
      typeDeserializer - Deserializer to use for handling type information
      Throws:
      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>

    • createContextual

      public JsonDeserializer<?> createContextual(DeserializationContext ctxt, BeanProperty property) throws JsonMappingException
      Description copied from interface: ContextualDeserializer
      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.
      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 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