com.fasterxml.jackson.databind.node

Class BaseJsonNode

java.lang.Object

com.fasterxml.jackson.databind.JsonNode

com.fasterxml.jackson.databind.node.BaseJsonNode

All Implemented Interfaces:

TreeNode, JsonSerializable, Iterable<JsonNode>

Direct Known Subclasses:

ContainerNode, ValueNode

public abstract class BaseJsonNode
extends JsonNode
implements JsonSerializable

Abstract base class common to all standard JsonNode implementations. The main addition here is that we declare that sub-classes must implement JsonSerializable. This simplifies object mapping aspects a bit, as no external serializers are needed.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BaseJsonNode()

Method Summary

Modifier and Type	Method and Description
abstract JsonToken	asToken() Method that can be used for efficient type detection when using stream abstraction for traversing nodes.
JsonNode	findPath(String fieldName) Method similar to JsonNode.findValue(java.lang.String), but that will return a "missing node" instead of null if no field is found.
JsonParser.NumberType	numberType() Returns code that identifies type of underlying numeric value, if (and only if) node is a number node.
abstract void	serialize(JsonGenerator jgen, SerializerProvider provider) Method called to serialize node instances using given generator.
abstract void	serializeWithType(JsonGenerator jgen, SerializerProvider provider, TypeSerializer typeSer) Type information is needed, even if JsonNode instances are "plain" JSON, since they may be mixed with other types.
JsonParser	traverse() Method for constructing a JsonParser instance for iterating over contents of the tree that this node is root of.
JsonParser	traverse(ObjectCodec codec) Same as TreeNode.traverse(), but additionally passes ObjectCodec to use if JsonParser.readValueAs(Class) is used (otherwise caller must call JsonParser.setCodec(com.fasterxml.jackson.core.ObjectCodec) on response explicitly).

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

_at, asBoolean, asBoolean, asDouble, asDouble, asInt, asInt, asLong, asLong, asText, asText, at, at, bigIntegerValue, binaryValue, booleanValue, canConvertToInt, canConvertToLong, decimalValue, deepCopy, doubleValue, elements, equals, fieldNames, fields, findParent, findParents, findParents, findValue, findValues, findValues, findValuesAsText, findValuesAsText, floatValue, get, get, getNodeType, has, has, hasNonNull, hasNonNull, intValue, isArray, isBigDecimal, isBigInteger, isBinary, isBoolean, isContainerNode, isDouble, isFloat, isFloatingPointNumber, isInt, isIntegralNumber, isLong, isMissingNode, isNull, isNumber, isObject, isPojo, isShort, isTextual, isValueNode, iterator, longValue, numberValue, path, path, shortValue, size, textValue, toString, with, withArray

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

BaseJsonNode

protected BaseJsonNode()

Method Detail

findPath

public final JsonNode findPath(String fieldName)

Description copied from class: JsonNode

Method similar to JsonNode.findValue(java.lang.String), but that will return a "missing node" instead of null if no field is found. Missing node is a specific kind of node for which JsonNode.isMissingNode() returns true; and all value access methods return empty or missing value.

Specified by:

findPath in class JsonNode

Parameters:

fieldName - Name of field to look for

Returns:

Value of first matching node found; or if not found, a "missing node" (non-null instance that has no value)

traverse

public JsonParser traverse()

Description copied from interface: TreeNode

Method for constructing a JsonParser instance for iterating over contents of the tree that this node is root of. Functionally equivalent to first serializing tree using ObjectCodec and then re-parsing but more efficient.

NOTE: constructed parser instance will NOT initially point to a token, so before passing it to deserializers, it is typically necessary to advance it to the first available token by calling JsonParser.nextToken().

Also note that calling this method will NOT pass ObjectCodec reference, so data-binding callback methods like JsonParser.readValueAs(Class) will not work with calling JsonParser.setCodec(com.fasterxml.jackson.core.ObjectCodec)). It is often better to call TreeNode.traverse(ObjectCodec) to pass the codec explicitly.

Specified by:

traverse in interface TreeNode

traverse

public JsonParser traverse(ObjectCodec codec)

Description copied from interface: TreeNode

Same as TreeNode.traverse(), but additionally passes ObjectCodec to use if JsonParser.readValueAs(Class) is used (otherwise caller must call JsonParser.setCodec(com.fasterxml.jackson.core.ObjectCodec) on response explicitly).

NOTE: constructed parser instance will NOT initially point to a token, so before passing it to deserializers, it is typically necessary to advance it to the first available token by calling JsonParser.nextToken().

Specified by:

traverse in interface TreeNode

asToken

public abstract JsonToken asToken()

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

numberType

public JsonParser.NumberType numberType()

Returns code that identifies type of underlying numeric value, if (and only if) node is a number node.

Specified by:

numberType in interface TreeNode

Returns:

Type of number contained, if any; or null if node does not contain numeric value.

serialize

public abstract void serialize(JsonGenerator jgen,
                               SerializerProvider provider)
                        throws IOException,
                               JsonProcessingException

Method called to serialize node instances using given generator.

Specified by:

serialize in interface JsonSerializable

Throws:

IOException

JsonProcessingException

serializeWithType

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

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

Throws:

IOException

JsonProcessingException