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>, TreeNode, JacksonSerializable

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 class tools.jackson.databind.JsonNode

JsonNode.OverwriteMode

Nested classes/interfaces inherited from interface tools.jackson.databind.JacksonSerializable

JacksonSerializable.Base

Field Summary

Fields

Modifier and Type	Field	Description
static final NullNode	instance

Fields inherited from class tools.jackson.databind.node.ValueNode

BD_MAX_INTEGER, BD_MAX_LONG, BD_MAX_SHORT, BD_MIN_INTEGER, BD_MIN_LONG, BD_MIN_SHORT, BI_MAX_INTEGER, BI_MAX_LONG, BI_MAX_SHORT, BI_MIN_INTEGER, BI_MIN_LONG, BI_MIN_SHORT, MISSING

Fields inherited from class tools.jackson.databind.node.BaseJsonNode

OPT_FALSE, OPT_TRUE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NullNode()

Method Summary

Modifier and Type	Method	Description
protected Boolean	_asBoolean()	Method sub-classes should override if they can produce boolean values via BaseJsonNode.asBoolean() -- if not, return null (in which case appropriate error will be thrown or default value returned).
protected String	_asString()	Method sub-classes should override if they can produce String values via BaseJsonNode.asString() -- if not, return null (in which case appropriate error will be thrown or default value returned).
protected String	_valueDesc()	Method for implementation classes to return a short description of contained value, to be used in error messages.
BigInteger	asBigInteger()	Method similar to JsonNode.bigIntegerValue() but in addition to coercing Number values (same as JsonNode.bigIntegerValue()), will also try to coerce a couple of additional types (or cases): JSON Floating-point numbers with fractions (ones without fractions are ok for JsonNode.bigIntegerValue()) will be truncated to integer value (like with BigDecimal.toBigInteger())) JSON Strings that represent JSON Numbers ("stringified" numbers) JSON Null (converted to 0)) POJO nodes that contain Number values
BigInteger	asBigInteger(BigInteger defaultValue)	Method similar to JsonNode.asBigInteger(), but that will return specified defaultValue if this node cannot be converted to BigInteger.
Optional<BigInteger>	asBigIntegerOpt()	Method similar to JsonNode.bigIntegerValue(), but that will return empty (Optional.empty()) if this node cannot be converted to Java BigInteger.
BigDecimal	asDecimal()	Method that will try to access value of this node as a BigDecimal: but if node value cannot be expressed exactly as a BigDecimal, a JsonNodeException will be thrown.
BigDecimal	asDecimal(BigDecimal defaultValue)	Method similar to JsonNode.asDecimal(), but that will return defaultValue if this node cannot be coerced to Java BigDecimal.
Optional<BigDecimal>	asDecimalOpt()	Method similar to JsonNode.asDecimal(), but that will return empty Optional (Optional.empty()) if this node cannot be coerced to BigDecimal.
double	asDouble()	Method similar to JsonNode.doubleValue() but in addition to coercing Number values will also try coerce couple of additional types: JSON String that represents JSON Numbers ("stringified" numbers) JSON Null (converted to 0.0d) POJO nodes that contain Number values
double	asDouble(double defaultValue)	Method similar to JsonNode.asDouble(), but that will return defaultValue if this node cannot be coerced to double.
OptionalDouble	asDoubleOpt()	Method similar to JsonNode.asDouble(), but that will return (OptionalDouble.empty()) if this node cannot be coerced to double.
float	asFloat()	Method similar to JsonNode.floatValue() but in addition to coercing Number values will also try coerce couple of additional types: JSON String that represents JSON Numbers ("stringified" numbers) JSON Null (converted to 0.0f) POJO nodes that contain Number values
float	asFloat(float defaultValue)	Method similar to JsonNode.asFloat(), but that will return defaultValue if this node cannot be coerced to float.
Optional<Float>	asFloatOpt()	Method similar to JsonNode.asFloat(), but that will return (Optional.empty()) if this node cannot be coerced to float.
int	asInt()	Method similar to JsonNode.intValue() but in addition to coercing Number values (same as JsonNode.intValue()), will also try to coerce a couple of additional types (or cases): JSON Floating-point numbers with fractions (ones without fractions are ok for JsonNode.intValue()) will be truncated to int (if (and only if) they fit in int range).
int	asInt(int defaultValue)	Method similar to JsonNode.intValue(), but that will return specified defaultValue if this node cannot be converted to int.
OptionalInt	asIntOpt()	Method similar to JsonNode.asInt(), but that will return (OptionalInt.empty()) if this node cannot be coerced to int.
long	asLong()	Method similar to JsonNode.longValue() but in addition to coercing Number values (same as JsonNode.longValue()), will also try to coerce a couple of additional types (or cases): JSON Floating-point numbers with fractions (ones without fractions are ok for JsonNode.longValue()) will be truncated to long (if (and only if) they fit in long range).
long	asLong(long defaultValue)	Method similar to JsonNode.asLong(), but that will return specified defaultValue if this node cannot be coerced to long (instead of throwing an exception).
OptionalLong	asLongOpt()	Method similar to JsonNode.asLong(), but that will return (OptionalLong.empty()) if this node cannot be coerced to long.
short	asShort()	Method similar to JsonNode.shortValue() but in addition to coercing Number values (same as JsonNode.shortValue()), will also try to coerce a couple of additional types (or cases): JSON Floating-point numbers with fractions (ones without fractions are ok for JsonNode.shortValue()) will be truncated to short (if (and only if) they fit in short range).
short	asShort(short defaultValue)	Method similar to JsonNode.shortValue(), but that will return specified defaultValue if this node cannot be converted to short.
Optional<Short>	asShortOpt()	Method similar to JsonNode.asShort(), but that will return (Optional.empty()) if this node cannot be coerced to short.
JsonToken	asToken()	Method that can be used for efficient type detection when using stream abstraction for traversing nodes.
NullNode	deepCopy()	All current value nodes are immutable, so we can just return them as is.
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).
final void	serialize(JsonGenerator g, SerializationContext provider)	Method called to serialize node instances using given generator.
String	stringValue()	Method that will try to access value of this node as a Java String which works if (and only if) node contains JSON String or null value: if not, a JsonNodeException will be thrown.
String	stringValue(String defaultValue)	Method similar to JsonNode.stringValue(), but that will return specified defaultValue if this node does not contain a JSON String.
Optional<String>	stringValueOpt()	Method similar to JsonNode.stringValue(), but that will return Optional.empty() if this node does not contain a JSON String (NOTE: JSON null is not considered a String here)

Methods inherited from class tools.jackson.databind.node.ValueNode

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

Methods inherited from class tools.jackson.databind.node.BaseJsonNode

_jsonPointerIfValid, _reportBigDecimalCoercionNaNFail, _reportBigIntegerCoercionFractionFail, _reportBigIntegerCoercionNaNFail, _reportCoercionFail, _reportDoubleCoercionRangeFail, _reportFloatCoercionRangeFail, _reportIntCoercionFractionFail, _reportIntCoercionNaNFail, _reportIntCoercionRangeFail, _reportLongCoercionFractionFail, _reportLongCoercionNaNFail, _reportLongCoercionRangeFail, _reportShortCoercionFractionFail, _reportShortCoercionRangeFail, _reportWrongNodeType, _withArray, _withObject, _withXxxMayReplace, _withXxxVerifyReplace, asBoolean, asBoolean, asBooleanOpt, asString, asString, asStringOpt, bigIntegerValue, bigIntegerValue, bigIntegerValueOpt, binaryValue, booleanValue, booleanValue, booleanValueOpt, decimalValue, decimalValue, decimalValueOpt, doubleValue, doubleValue, doubleValueOpt, findPath, floatValue, floatValue, floatValueOpt, intValue, intValue, intValueOpt, isEmbeddedValue, isMissingNode, longValue, longValue, longValueOpt, numberType, numberValue, required, required, shortValue, shortValue, shortValueOpt, toPrettyString, toString, traverse, withArray, withObject

Methods inherited from class tools.jackson.databind.JsonNode

_reportRequiredViolation, _reportUnsupportedOperation, _this, asOptional, asText, asText, at, at, canConvertToExactIntegral, canConvertToInt, canConvertToLong, canConvertToShort, equals, findParents, findValues, findValuesAsString, forEachEntry, isArray, isBigDecimal, isBigInteger, isBinary, isBoolean, isContainer, isDouble, isFloat, isFloatingPointNumber, isInt, isIntegralNumber, isLong, isNull, isNumber, isObject, isPojo, isShort, isString, isTextual, isValueNode, iterator, optional, optional, properties, propertyNames, propertyStream, require, requiredAt, requiredAt, size, spliterator, textValue, values, valueStream, withArray, withArray, withArray, withArrayProperty, withObject, withObject, withObject, withObjectProperty

Methods inherited from class tools.jackson.databind.JacksonSerializable.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

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 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

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.

_asBoolean

protected Boolean _asBoolean()

Description copied from class: BaseJsonNode

Method sub-classes should override if they can produce boolean values via BaseJsonNode.asBoolean() -- if not, return null (in which case appropriate error will be thrown or default value returned).

Overrides:

_asBoolean in class BaseJsonNode

Returns:

Coerced value if possible; otherwise null to indicate this node cannot be coerced.

_asString

protected String _asString()

Description copied from class: BaseJsonNode

Method sub-classes should override if they can produce String values via BaseJsonNode.asString() -- if not, return null (in which case appropriate error will be thrown or default value returned).

Overrides:

_asString in class BaseJsonNode

Returns:

Coerced value if possible; otherwise null to indicate this node cannot be coerced.

stringValue

public String stringValue()

Description copied from class: JsonNode

Method that will try to access value of this node as a Java String which works if (and only if) node contains JSON String or null value: if not, a JsonNodeException will be thrown. In case of JSON null, Java null is returned.

NOTE: for more conversions, use JsonNode.asString() instead.

NOTE: in Jackson 2.x, this method was named textValue().

Overrides:

stringValue in class BaseJsonNode

Returns:

String value this node represents (if JSON String), null for JSON null

stringValue

public String stringValue(String defaultValue)

Description copied from class: JsonNode

Method similar to JsonNode.stringValue(), but that will return specified defaultValue if this node does not contain a JSON String. This default value case includes JSON null.

Overrides:

stringValue in class BaseJsonNode

Parameters:

defaultValue - Value to return if this node does not contain a JSON String.

Returns:

Java String value this node represents (if JSON String); defaultValue otherwise -- only returns null if defaultValue is null

stringValueOpt

public Optional<String> stringValueOpt()

Description copied from class: JsonNode

Method similar to JsonNode.stringValue(), but that will return Optional.empty() if this node does not contain a JSON String (NOTE: JSON null is not considered a String here)

Overrides:

stringValueOpt in class BaseJsonNode

Returns:

Optional<String> value (if node represents JSON String); Optional.empty() otherwise (including for JSON null)

asShort

public short asShort()

Description copied from class: JsonNode

Method similar to JsonNode.shortValue() but in addition to coercing Number values (same as JsonNode.shortValue()), will also try to coerce a couple of additional types (or cases):

• JSON Floating-point numbers with fractions (ones without fractions are ok for JsonNode.shortValue()) will be truncated to short (if (and only if) they fit in short range).
• JSON Strings that represent JSON Numbers ("stringified" numbers)
• JSON Null (converted to 0))
• POJO nodes that contain Number values

Overrides:

asShort in class BaseJsonNode

Returns:

short value this node represents, if possible to accurately represent

asShort

public short asShort(short defaultValue)

Description copied from class: JsonNode

Method similar to JsonNode.shortValue(), but that will return specified defaultValue if this node cannot be converted to short.

Overrides:

asShort in class BaseJsonNode

Parameters:

defaultValue - Value to return if this node cannot be converted to short

Returns:

short value this node represents, if possible to accurately represent; defaultValue otherwise

asShortOpt

public Optional<Short> asShortOpt()

Description copied from class: JsonNode

Method similar to JsonNode.asShort(), but that will return (Optional.empty()) if this node cannot be coerced to short.

Overrides:

asShortOpt in class BaseJsonNode

Returns:

Optional<Short> value this node represents, if possible to accurately represent; Optional.empty() otherwise

asInt

public int asInt()

Description copied from class: JsonNode

Method similar to JsonNode.intValue() but in addition to coercing Number values (same as JsonNode.intValue()), will also try to coerce a couple of additional types (or cases):

• JSON Floating-point numbers with fractions (ones without fractions are ok for JsonNode.intValue()) will be truncated to int (if (and only if) they fit in int range).
• JSON Strings that represent JSON Numbers ("stringified" numbers)
• JSON Null (converted to 0))
• POJO nodes that contain Number values

Overrides:

asInt in class BaseJsonNode

Returns:

int value this node represents, if possible to accurately represent

asInt

public int asInt(int defaultValue)

Description copied from class: JsonNode

Method similar to JsonNode.intValue(), but that will return specified defaultValue if this node cannot be converted to int.

Overrides:

asInt in class BaseJsonNode

Parameters:

defaultValue - Value to return if this node cannot be converted to int

Returns:

int value this node represents, if possible to accurately represent; defaultValue otherwise

asIntOpt

public OptionalInt asIntOpt()

Description copied from class: JsonNode

Method similar to JsonNode.asInt(), but that will return (OptionalInt.empty()) if this node cannot be coerced to int.

Overrides:

asIntOpt in class BaseJsonNode

Returns:

OptionalInt value this node represents, if possible to accurately represent; OptionalInt.empty() otherwise

asLong

public long asLong()

Description copied from class: JsonNode

Method similar to JsonNode.longValue() but in addition to coercing Number values (same as JsonNode.longValue()), will also try to coerce a couple of additional types (or cases):

• JSON Floating-point numbers with fractions (ones without fractions are ok for JsonNode.longValue()) will be truncated to long (if (and only if) they fit in long range).
• JSON Strings that represent JSON Numbers ("stringified" numbers)
• JSON Null (converted to 0))
• POJO nodes that contain Number values

Overrides:

asLong in class BaseJsonNode

Returns:

long value this node represents, if possible to accurately represent

asLong

public long asLong(long defaultValue)

Description copied from class: JsonNode

Method similar to JsonNode.asLong(), but that will return specified defaultValue if this node cannot be coerced to long (instead of throwing an exception).

Overrides:

asLong in class BaseJsonNode

Parameters:

defaultValue - Value to return if this node cannot be coerced to long

Returns:

long value this node represents, if possible to accurately represent; defaultValue otherwise

asLongOpt

public OptionalLong asLongOpt()

Description copied from class: JsonNode

Method similar to JsonNode.asLong(), but that will return (OptionalLong.empty()) if this node cannot be coerced to long.

Overrides:

asLongOpt in class BaseJsonNode

Returns:

OptionalLong value this node represents (or can be coerced to), OptionalLong.empty() otherwise

asBigInteger

public BigInteger asBigInteger()

Description copied from class: JsonNode

Method similar to JsonNode.bigIntegerValue() but in addition to coercing Number values (same as JsonNode.bigIntegerValue()), will also try to coerce a couple of additional types (or cases):

• JSON Floating-point numbers with fractions (ones without fractions are ok for JsonNode.bigIntegerValue()) will be truncated to integer value (like with BigDecimal.toBigInteger()))
• JSON Strings that represent JSON Numbers ("stringified" numbers)
• JSON Null (converted to 0))
• POJO nodes that contain Number values

Overrides:

asBigInteger in class BaseJsonNode

Returns:

BigInteger value this node represents, if possible to accurately convert; defaultValue otherwise

asBigInteger

public BigInteger asBigInteger(BigInteger defaultValue)

Description copied from class: JsonNode

Method similar to JsonNode.asBigInteger(), but that will return specified defaultValue if this node cannot be converted to BigInteger.

Overrides:

asBigInteger in class BaseJsonNode

Parameters:

defaultValue - Value to return if this node cannot be converted to BigInteger

Returns:

BigInteger value this node represents, if possible to accurately convert; defaultValue otherwise

asBigIntegerOpt

public Optional<BigInteger> asBigIntegerOpt()

Description copied from class: JsonNode

Method similar to JsonNode.bigIntegerValue(), but that will return empty (Optional.empty()) if this node cannot be converted to Java BigInteger.

Overrides:

asBigIntegerOpt in class BaseJsonNode

Returns:

BigInteger value this node represents, as Optional<BigInteger>, if possible to accurately represent; Optional.empty() otherwise.

asFloat

public float asFloat()

Description copied from class: JsonNode

Method similar to JsonNode.floatValue() but in addition to coercing Number values will also try coerce couple of additional types:

• JSON String that represents JSON Numbers ("stringified" numbers)
• JSON Null (converted to 0.0f)
• POJO nodes that contain Number values

Overrides:

asFloat in class BaseJsonNode

Returns:

float value this node represents, if possible to accurately represent

asFloat

public float asFloat(float defaultValue)

Description copied from class: JsonNode

Method similar to JsonNode.asFloat(), but that will return defaultValue if this node cannot be coerced to float.

Overrides:

asFloat in class BaseJsonNode

Returns:

float value this node represents, if possible to accurately represent; defaultValue otherwise

asFloatOpt

public Optional<Float> asFloatOpt()

Description copied from class: JsonNode

Method similar to JsonNode.asFloat(), but that will return (Optional.empty()) if this node cannot be coerced to float.

Overrides:

asFloatOpt in class BaseJsonNode

Returns:

Optional<Float> value this node represents, if possible to accurately represent; Optional.empty() otherwise

asDouble

public double asDouble()

Description copied from class: JsonNode

Method similar to JsonNode.doubleValue() but in addition to coercing Number values will also try coerce couple of additional types:

• JSON String that represents JSON Numbers ("stringified" numbers)
• JSON Null (converted to 0.0d)
• POJO nodes that contain Number values

Overrides:

asDouble in class BaseJsonNode

Returns:

double value this node represents, if possible to accurately represent

asDouble

public double asDouble(double defaultValue)

Description copied from class: JsonNode

Method similar to JsonNode.asDouble(), but that will return defaultValue if this node cannot be coerced to double.

Overrides:

asDouble in class BaseJsonNode

Returns:

double value this node represents, if possible to accurately represent; defaultValue otherwise

asDoubleOpt

public OptionalDouble asDoubleOpt()

Description copied from class: JsonNode

Method similar to JsonNode.asDouble(), but that will return (OptionalDouble.empty()) if this node cannot be coerced to double.

Overrides:

asDoubleOpt in class BaseJsonNode

Returns:

OptionalDouble value this node represents, if possible to accurately represent; OptionalDouble.empty() otherwise

asDecimal

public BigDecimal asDecimal()

Description copied from class: JsonNode

Method that will try to access value of this node as a BigDecimal: but if node value cannot be expressed exactly as a BigDecimal, a JsonNodeException will be thrown. Access works for following cases:

• JSON Floating-point values (but not "NaN" or "Infinity")
• JSON Integer values
• JSON String that represents JSON Numbers ("stringified" numbers)
• JSON Null (converted to BigDecimal.ZERO))
• POJO nodes that contain Number values

Overrides:

asDecimal in class BaseJsonNode

Returns:

BigDecimal value this node represents, if possible to accurately represent

asDecimal

public BigDecimal asDecimal(BigDecimal defaultValue)

Description copied from class: JsonNode

Method similar to JsonNode.asDecimal(), but that will return defaultValue if this node cannot be coerced to Java BigDecimal.

Overrides:

asDecimal in class BaseJsonNode

Returns:

BigDecimal value this node represents, if possible to accurately represent; defaultValue otherwise

asDecimalOpt

public Optional<BigDecimal> asDecimalOpt()

Description copied from class: JsonNode

Method similar to JsonNode.asDecimal(), but that will return empty Optional (Optional.empty()) if this node cannot be coerced to BigDecimal.

Overrides:

asDecimalOpt in class BaseJsonNode

Returns:

Java BigDecimal value this node represents, as Optional<BigDecimal>, if possible to accurately represent; Optional.empty() otherwise

_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

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(JsonGenerator g,
 SerializationContext provider)
                     throws 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:

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