Module tools.jackson.databind
Package tools.jackson.databind.node

Class NullNode

java.lang.Object
tools.jackson.databind.JacksonSerializable.Base
tools.jackson.databind.JsonNode
tools.jackson.databind.node.BaseJsonNode
tools.jackson.databind.node.ValueNode
tools.jackson.databind.node.NullNode
All Implemented Interfaces:
Serializable, Iterable<JsonNode>, tools.jackson.core.TreeNode, JacksonSerializable
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()

  • Method Details

    • getInstance

      public static NullNode getInstance()

    • readResolve

      protected Object readResolve()

    • 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 tools.jackson.core.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 tools.jackson.core.TreeNode
      Specified by:
      asToken in class ValueNode

    • deepCopy

      public NullNode deepCopy()
      Description copied from class: ValueNode
      All current value nodes are immutable, so we can just return them as is.
      Overrides:
      deepCopy in class ValueNode
      Returns:
      Node that is either a copy of this node (and all non-leaf children); or, for immutable leaf nodes, node itself.

    • _valueDesc

      protected String _valueDesc()
      Description copied from class: BaseJsonNode
      Method for implementation classes to return a short description of contained value, to be used in error messages.
      Specified by:
      _valueDesc in class BaseJsonNode

    • asString

      public String asString(String defaultValue)
      Description copied from class: JsonNode
      Returns the text value of this node or the provided defaultValue if this node does not have a text value. Useful for nodes that are MissingNode or NullNode, ensuring a default value is returned instead of null or missing indicators.
      Overrides:
      asString in class BaseJsonNode
      Parameters:
      defaultValue - The default value to return if this node's text value is absent.
      Returns:
      The text value of this node, or defaultValue if the text value is absent.

    • asString

      public String asString()
      Description copied from class: JsonNode
      Method that will return a valid String representation of the contained value, if the node is a value node (method JsonNode.isValueNode() returns true), otherwise empty String.

      NOTE: this is NOT same as JsonNode.toString() in that result is

      NOT VALID ENCODED JSON

      for all nodes (but is for some, like NumberNodes and BooleanNodes).
      Specified by:
      asString 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 exception is thrown.
      Overrides:
      requireNonNull in class JsonNode
      Returns:
      this node to allow chaining

    • serialize

      public final void serialize(tools.jackson.core.JsonGenerator g, SerializationContext provider) throws tools.jackson.core.JacksonException
      Description copied from class: BaseJsonNode
      Method called to serialize node instances using given generator.
      Specified by:
      serialize in interface JacksonSerializable
      Specified by:
      serialize in class BaseJsonNode
      Throws:
      tools.jackson.core.JacksonException

    • 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