com.fasterxml.jackson.databind.node

Class MissingNode

java.lang.Object

com.fasterxml.jackson.databind.JsonNode

com.fasterxml.jackson.databind.node.BaseJsonNode

com.fasterxml.jackson.databind.node.MissingNode

All Implemented Interfaces:

TreeNode, JsonSerializable, Iterable<JsonNode>

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.

Field Summary

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

NO_NODES, NO_STRINGS

Method Summary

Methods

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.
JsonToken	asToken() Method that can be used for efficient type detection when using stream abstraction for traversing nodes.
<T extends JsonNode> T	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.
static MissingNode	getInstance()
boolean	isMissingNode() Method that returns true for "virtual" nodes which represent missing entries constructed by path accessor methods when there is no actual node matching given criteria.
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.
void	serialize(JsonGenerator jg, SerializerProvider provider) Method called to serialize node instances using given generator.
void	serializeWithType(JsonGenerator jg, SerializerProvider provider, TypeSerializer typeSer) Type information is needed, even if JsonNode instances are "plain" JSON, since they may be mixed with other types.
String	toString() Note: marked as abstract to ensure all implementation classes define it properly.

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

findParent, findParents, findPath, findValue, findValues, findValuesAsText, numberType, traverse

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

asBoolean, asBoolean, asDouble, asDouble, asInt, asInt, asLong, asLong, bigIntegerValue, binaryValue, booleanValue, canConvertToInt, canConvertToLong, decimalValue, doubleValue, elements, fieldNames, fields, findParents, findValues, findValuesAsText, get, get, has, has, hasNonNull, hasNonNull, intValue, isArray, isBigDecimal, isBigInteger, isBinary, isBoolean, isContainerNode, isDouble, isFloatingPointNumber, isInt, isIntegralNumber, isLong, isNull, isNumber, isObject, isPojo, isTextual, isValueNode, iterator, longValue, numberValue, size, textValue, with, withArray

Methods inherited from class java.lang.Object

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

Method Detail

deepCopy

public <T extends JsonNode> T 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()

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

isMissingNode

public boolean isMissingNode()

Description copied from class: JsonNode

Method that returns true for "virtual" nodes which represent missing entries constructed by path accessor methods when there is no actual node matching given criteria.

Note: one and only one of methods JsonNode.isValueNode(), JsonNode.isContainerNode() and JsonNode.isMissingNode() ever returns true for any given node.

Overrides:

isMissingNode 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

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 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 class JsonNode

serialize

public final void serialize(JsonGenerator jg,
             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 jg,
                     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

Specified by:

serializeWithType in class BaseJsonNode

Throws:

IOException

JsonProcessingException

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

toString

public String toString()

Description copied from class: JsonNode

Note: marked as abstract to ensure all implementation classes define it properly.

Specified by:

toString in class JsonNode