com.fasterxml.jackson.databind.node

Class NullNode

java.lang.Object

com.fasterxml.jackson.databind.JsonSerializable.Base

com.fasterxml.jackson.databind.JsonNode

com.fasterxml.jackson.databind.node.BaseJsonNode

com.fasterxml.jackson.databind.node.ValueNode

com.fasterxml.jackson.databind.node.NullNode

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:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.fasterxml.jackson.databind.JsonSerializable

JsonSerializable.Base

Field Summary

Fields

Modifier and Type	Field and Description
static NullNode	instance

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	NullNode() NOTE: visibility raised to `protected` in 2.9.3 to allow custom subtypes.

Method Summary

Modifier and Type	Method and Description
String	asText() 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.
String	asText(String defaultValue) 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.
JsonToken	asToken() Method that can be used for efficient type detection when using stream abstraction for traversing nodes.
boolean	equals(Object o) Equality for node objects is defined as full (deep) value equality.
static NullNode	getInstance()
JsonNodeType	getNodeType() Return the type of this node
int	hashCode()
protected Object	readResolve()
JsonNode	requireNonNull() 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).
void	serialize(JsonGenerator g, SerializerProvider provider) Method called to serialize node instances using given generator.

Methods inherited from class com.fasterxml.jackson.databind.node.ValueNode

_at, deepCopy, findParent, findParents, findValue, findValues, findValuesAsText, get, get, has, has, hasNonNull, hasNonNull, isEmpty, path, path, serializeWithType

Methods inherited from class com.fasterxml.jackson.databind.node.BaseJsonNode

findPath, numberType, required, required, toPrettyString, toString, traverse, traverse

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

_reportRequiredViolation, _this, asBoolean, asBoolean, asDouble, asDouble, asInt, asInt, asLong, asLong, at, at, bigIntegerValue, binaryValue, booleanValue, canConvertToInt, canConvertToLong, decimalValue, doubleValue, elements, equals, fieldNames, fields, findParents, findValues, findValuesAsText, floatValue, intValue, isArray, isBigDecimal, isBigInteger, isBinary, isBoolean, isContainerNode, isDouble, isFloat, isFloatingPointNumber, isInt, isIntegralNumber, isLong, isMissingNode, isNull, isNumber, isObject, isPojo, isShort, isTextual, isValueNode, iterator, longValue, numberValue, require, requiredAt, requiredAt, shortValue, size, textValue, with, withArray

Methods inherited from class com.fasterxml.jackson.databind.JsonSerializable.Base

isEmpty

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

instance

public static final NullNode instance

Constructor Detail

NullNode

protected NullNode()

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

Method Detail

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

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