All Implemented Interfaces:
TreeNode, JsonSerializable, Serializable, Iterable<JsonNode>

public class NullNode extends ValueNode
This singleton value class is used to contain explicit JSON null value.
See Also:
  • Field Details

    • instance

      public static final NullNode instance
  • Constructor Details

    • NullNode

      protected NullNode()

      NOTE: visibility raised to `protected` in 2.9.3 to allow custom subtypes.

  • Method Details

    • readResolve

      protected Object readResolve()
    • getInstance

      public static NullNode getInstance()
    • getNodeType

      public JsonNodeType getNodeType()
      Description copied from class: JsonNode
      Return the type of this node
      Specified by:
      getNodeType in class JsonNode
      Returns:
      the node type as a JsonNodeType enum value
    • asToken

      public JsonToken asToken()
      Description copied from class: BaseJsonNode
      Method that can be used for efficient type detection when using stream abstraction for traversing nodes. Will return the first JsonToken that equivalent stream event would produce (for most nodes there is just one token but for structured/container types multiple)
      Specified by:
      asToken in interface TreeNode
      Specified by:
      asToken in class ValueNode
      Returns:
      JsonToken that is most closely associated with the node type
    • asText

      public String asText(String defaultValue)
      Description copied from class: JsonNode
      Method similar to JsonNode.asText(), except that it will return defaultValue in cases where null value would be returned; either for missing nodes (trying to access missing property, or element at invalid item for array) or explicit nulls.
      Overrides:
      asText in class JsonNode
    • asText

      public String asText()
      Description copied from class: JsonNode
      Method that will return a valid String representation of the container value, if the node is a value node (method JsonNode.isValueNode() returns true), otherwise empty String.
      Specified by:
      asText in class JsonNode
    • requireNonNull

      public JsonNode requireNonNull()
      Description copied from class: JsonNode
      Method that may be called to verify that this node is neither so-called "missing node" (that is, one for which JsonNode.isMissingNode() returns true) nor "null node" (one for which JsonNode.isNull() returns true). If non-null non-missing node, this is returned to allow chaining; otherwise IllegalArgumentException is thrown.
      Overrides:
      requireNonNull in class JsonNode
      Returns:
      this node to allow chaining
    • serialize

      public final void serialize(JsonGenerator g, SerializerProvider provider) throws IOException
      Description copied from class: BaseJsonNode
      Method called to serialize node instances using given generator.
      Specified by:
      serialize in interface JsonSerializable
      Specified by:
      serialize in class BaseJsonNode
      Throws:
      IOException
    • equals

      public boolean equals(Object o)
      Description copied from class: JsonNode
      Equality for node objects is defined as full (deep) value equality. This means that it is possible to compare complete JSON trees for equality by comparing equality of root nodes.

      Note: marked as abstract to ensure all implementation classes define it properly and not rely on definition from Object.

      Specified by:
      equals in class JsonNode
    • hashCode

      public int hashCode()
      Specified by:
      hashCode in class BaseJsonNode