Module tools.jackson.databind

Package tools.jackson.databind.node

Class MissingNode

java.lang.Object

tools.jackson.databind.JacksonSerializable.Base

tools.jackson.databind.JsonNode

tools.jackson.databind.node.BaseJsonNode

tools.jackson.databind.node.MissingNode

All Implemented Interfaces:

Serializable, Iterable<JsonNode>, TreeNode, JacksonSerializable

public final class MissingNode
extends BaseJsonNode

This singleton node class is generated to denote "missing nodes" along paths that do not exist. For example, if a path via element of an array is requested for an element outside range of elements in the array; or for a non-array value, result will be reference to this node.

In most respects this placeholder node will act as NullNode; for example, for purposes of value conversions, value is considered to be null and represented as value zero when used for numeric conversions.

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

OPT_FALSE, OPT_TRUE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	MissingNode()

Method Summary

Modifier and Type	Method	Description
protected JsonNode	_at(JsonPointer ptr)	Helper method used by other methods for traversing the next step of given path expression, and returning matching value node if any: if no match, null is returned.
protected String	_valueDesc()	Method for implementation classes to return a short description of contained value, to be used in error messages.
Optional<JsonNode>	asOptional()	Method that will return a JsonNode wrapped in Java's Optional.
JsonToken	asToken()	Method that can be used for efficient type detection when using stream abstraction for traversing nodes.
MissingNode	deepCopy()	Method that can be called to get a node that is guaranteed not to allow changing of this node through mutators on this node or any of its children.
boolean	equals(Object o)	Equality for node objects is defined as full (deep) value equality.
JsonNode	findParent(String fieldName)	Method for finding a JSON Object that contains specified field, within this node or its descendants.
List<JsonNode>	findParents(String fieldName, List<JsonNode> foundSoFar)
JsonNode	findValue(String fieldName)	Method for finding the first JSON Object field with specified name in this node or its child nodes, and returning value it has.
List<JsonNode>	findValues(String fieldName, List<JsonNode> foundSoFar)
List<String>	findValuesAsString(String fieldName, List<String> foundSoFar)
JsonNode	get(int index)	Method for accessing value of the specified element of an array node.
static MissingNode	getInstance()
JsonNodeType	getNodeType()	Return the type of this node
int	hashCode()
final boolean	isMissingNode()
JsonNode	path(int index)	This method is similar to JsonNode.get(int), except that instead of returning null if no such element exists (due to index being out of range, or this node not being an array), a "missing node" (node that returns true for JsonNode.isMissingNode()) will be returned.
JsonNode	path(String fieldName)	This method is similar to JsonNode.get(String), except that instead of returning null if no such value exists (due to this node not being an object, or object not having value for the specified field), a "missing node" (node that returns true for JsonNode.isMissingNode()) will be returned.
protected Object	readResolve()
JsonNode	require()	Method that may be called to verify that this node is NOT so-called "missing node": that is, one for which JsonNode.isMissingNode() returns true.
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.
void	serializeWithType(JsonGenerator g, SerializationContext provider, TypeSerializer typeSer)	Type information is needed, even if JsonNode instances are "plain" JSON, since they may be mixed with other types.
String	toPrettyString()	Alternative to JsonNode.toString() that will serialize this node using Jackson default pretty-printer.
String	toString()	Method that will produce (as of Jackson 2.10) valid JSON using default settings of databind, as String.

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

_asBoolean, _asString, _jsonPointerIfValid, _reportBigDecimalCoercionNaNFail, _reportBigIntegerCoercionFractionFail, _reportBigIntegerCoercionNaNFail, _reportCoercionFail, _reportDoubleCoercionRangeFail, _reportFloatCoercionRangeFail, _reportIntCoercionFractionFail, _reportIntCoercionNaNFail, _reportIntCoercionRangeFail, _reportLongCoercionFractionFail, _reportLongCoercionNaNFail, _reportLongCoercionRangeFail, _reportShortCoercionFractionFail, _reportShortCoercionRangeFail, _reportWrongNodeType, _withArray, _withObject, _withXxxMayReplace, _withXxxVerifyReplace, asBigInteger, asBigInteger, asBigIntegerOpt, asBoolean, asBoolean, asBooleanOpt, asDecimal, asDecimal, asDecimalOpt, asDouble, asDouble, asDoubleOpt, asFloat, asFloat, asFloatOpt, asInt, asInt, asIntOpt, asLong, asLong, asLongOpt, asShort, asShort, asShortOpt, asString, asString, asStringOpt, bigIntegerValue, bigIntegerValue, bigIntegerValueOpt, binaryValue, booleanValue, booleanValue, booleanValueOpt, decimalValue, decimalValue, decimalValueOpt, doubleValue, doubleValue, doubleValueOpt, findPath, floatValue, floatValue, floatValueOpt, intValue, intValue, intValueOpt, isEmbeddedValue, longValue, longValue, longValueOpt, numberType, numberValue, required, required, shortValue, shortValue, shortValueOpt, stringValue, stringValue, stringValueOpt, traverse, withArray, withObject

Methods inherited from class tools.jackson.databind.JsonNode

_reportRequiredViolation, _reportUnsupportedOperation, _this, asText, asText, at, at, canConvertToExactIntegral, canConvertToInt, canConvertToLong, canConvertToShort, equals, findParents, findValues, findValuesAsString, forEachEntry, get, has, has, hasNonNull, hasNonNull, isArray, isBigDecimal, isBigInteger, isBinary, isBoolean, isContainer, isDouble, isEmpty, isFloat, isFloatingPointNumber, isInt, isIntegralNumber, isLong, isNull, isNumber, isObject, isPojo, isShort, isString, isTextual, isValueNode, iterator, optional, optional, properties, propertyNames, propertyStream, 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

Constructor Details

MissingNode

protected MissingNode()

Method Details

readResolve

protected Object readResolve()

deepCopy

public MissingNode deepCopy()

Description copied from class: JsonNode

Method that can be called to get a node that is guaranteed not to allow changing of this node through mutators on this node or any of its children. This means it can either make a copy of this node (and all mutable children and grand children nodes), or node itself if it is immutable.

Note: return type is guaranteed to have same type as the node method is called on; which is why method is declared with local generic type.

Specified by:

deepCopy in class JsonNode

Returns:

Node that is either a copy of this node (and all non-leaf children); or, for immutable leaf nodes, node itself.

getInstance

public static MissingNode 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

isMissingNode

public final boolean isMissingNode()

Specified by:

isMissingNode in interface TreeNode

Overrides:

isMissingNode in class BaseJsonNode

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 BaseJsonNode

_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

asOptional

public Optional<JsonNode> asOptional()

Description copied from class: JsonNode

Method that will return a JsonNode wrapped in Java's Optional. All nodes except of MissingNode will return non-empty Optional; MissingNode will return empty Optional.

Overrides:

asOptional in class JsonNode

Returns:

Optional<JsonNode> containing this node, or Optional.empty() if this is a MissingNode.

require

public JsonNode require()

Description copied from class: JsonNode

Method that may be called to verify that this node is NOT so-called "missing node": that is, one for which JsonNode.isMissingNode() returns true. If not missing node, this is returned to allow chaining; otherwise exception is thrown.

Overrides:

require in class JsonNode

Returns:

this node to allow chaining

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

get

public JsonNode get(int index)

Description copied from class: JsonNode

Method for accessing value of the specified element of an array node. For other nodes, null is always returned.

For array nodes, index specifies exact location within array and allows for efficient iteration over child elements (underlying storage is guaranteed to be efficiently indexable, i.e. has random-access to elements). If index is less than 0, or equal-or-greater than node.size(), null is returned; no exception is thrown for any index.

NOTE: if the element value has been explicitly set as null (which is different from removal!), a NullNode will be returned, not null.

Specified by:

get in interface TreeNode

Specified by:

get in class JsonNode

Returns:

Node that represent value of the specified element, if this node is an array and has specified element. Null otherwise.

path

public JsonNode path(String fieldName)

Description copied from class: JsonNode

This method is similar to JsonNode.get(String), except that instead of returning null if no such value exists (due to this node not being an object, or object not having value for the specified field), a "missing node" (node that returns true for JsonNode.isMissingNode()) will be returned. This allows for convenient and safe chained access via path calls.

Specified by:

path in interface TreeNode

Specified by:

path in class JsonNode

path

public JsonNode path(int index)

Description copied from class: JsonNode

This method is similar to JsonNode.get(int), except that instead of returning null if no such element exists (due to index being out of range, or this node not being an array), a "missing node" (node that returns true for JsonNode.isMissingNode()) will be returned. This allows for convenient and safe chained access via path calls.

Specified by:

path in interface TreeNode

Specified by:

path in class JsonNode

_at

protected JsonNode _at(JsonPointer ptr)

Description copied from class: JsonNode

Helper method used by other methods for traversing the next step of given path expression, and returning matching value node if any: if no match, null is returned.

Specified by:

_at in class JsonNode

Parameters:

ptr - Path expression to use

Returns:

Either matching JsonNode for the first step of path or null if no match (including case that this node is not a container)

findValue

public JsonNode findValue(String fieldName)

Description copied from class: JsonNode

Method for finding the first JSON Object field with specified name in this node or its child nodes, and returning value it has. If no matching field is found in this node or its descendants, returns null.

Note that traversal is done in document order (that is, order in which nodes are iterated if using JsonNode.values())

Specified by:

findValue in class JsonNode

Parameters:

fieldName - Name of field to look for

Returns:

Value of first matching node found, if any; null if none

findParent

public JsonNode findParent(String fieldName)

Description copied from class: JsonNode

Method for finding a JSON Object that contains specified field, within this node or its descendants. If no matching field is found in this node or its descendants, returns null.

Specified by:

findParent in class JsonNode

Parameters:

fieldName - Name of field to look for

Returns:

Value of first matching node found, if any; null if none

findValues

public List<JsonNode> findValues(String fieldName,
 List<JsonNode> foundSoFar)

Specified by:

findValues in class JsonNode

findValuesAsString

public List<String> findValuesAsString(String fieldName,
 List<String> foundSoFar)

Specified by:

findValuesAsString in class JsonNode

findParents

public List<JsonNode> findParents(String fieldName,
 List<JsonNode> foundSoFar)

Specified by:

findParents in class JsonNode

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

serializeWithType

public void serializeWithType(JsonGenerator g,
 SerializationContext provider,
 TypeSerializer typeSer)
                       throws JacksonException

Description copied from class: BaseJsonNode

Type information is needed, even if JsonNode instances are "plain" JSON, since they may be mixed with other types.

Specified by:

serializeWithType in interface JacksonSerializable

Specified by:

serializeWithType 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

toString

public String toString()

Description copied from class: JsonNode

Method that will produce (as of Jackson 2.10) valid JSON using default settings of databind, as String. If you want other kinds of JSON output (or output formatted using one of other Jackson-supported data formats) make sure to use ObjectMapper or ObjectWriter to serialize an instance, for example:

   String json = objectMapper.writeValueAsString(rootNode);

Note: method defined as abstract to ensure all implementation classes explicitly implement method, instead of relying on Object.toString() definition.

Overrides:

toString in class BaseJsonNode

toPrettyString

public String toPrettyString()

Description copied from class: JsonNode

Alternative to JsonNode.toString() that will serialize this node using Jackson default pretty-printer.

Overrides:

toPrettyString in class BaseJsonNode