com.fasterxml.jackson.databind.node

Class MissingNode

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.MissingNode

All Implemented Interfaces:

TreeNode, JsonSerializable, Serializable, Iterable<JsonNode>

public final class MissingNode
extends ValueNode

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 interface com.fasterxml.jackson.databind.JsonSerializable

JsonSerializable.Base

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MissingNode() NOTE: visibility raised to `protected` in 2.9.3 to allow custom subtypes (which may not be greatest idea ever to have but was requested)

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.
<T extends JsonNode> T	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 MissingNode	getInstance()
JsonNodeType	getNodeType() Return the type of this node
int	hashCode()
boolean	isMissingNode()
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).
void	serialize(JsonGenerator g, SerializerProvider provider) Method called to serialize node instances using given generator.
void	serializeWithType(JsonGenerator g, SerializerProvider 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 com.fasterxml.jackson.databind.node.ValueNode

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

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

findPath, numberType, required, required, 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, isNull, isNumber, isObject, isPojo, isShort, isTextual, isValueNode, iterator, longValue, numberValue, 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

Constructor Detail

MissingNode

protected MissingNode()

NOTE: visibility raised to `protected` in 2.9.3 to allow custom subtypes (which may not be greatest idea ever to have but was requested)

Method Detail

readResolve

protected Object readResolve()

isMissingNode

public boolean isMissingNode()

Specified by:

isMissingNode in interface TreeNode

Overrides:

isMissingNode in class JsonNode

deepCopy

public <T extends JsonNode> T 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.

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

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()

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

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

serialize

public final void serialize(JsonGenerator g,
                            SerializerProvider provider)
                     throws IOException,
                            JsonProcessingException

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

JsonProcessingException

serializeWithType

public void serializeWithType(JsonGenerator g,
                              SerializerProvider provider,
                              TypeSerializer typeSer)
                       throws IOException,
                              JsonProcessingException

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 JsonSerializable

Overrides:

serializeWithType in class ValueNode

Throws:

IOException

JsonProcessingException

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 IllegalArgumentException 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 IllegalArgumentException is thrown.

Overrides:

requireNonNull in class JsonNode

Returns:

this node to allow chaining

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

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