Jackson-core 2.16.0 · com.fasterxml.jackson.core.TreeNode

Method Summary

Modifier and Type	Method and Description
public JsonToken	Returns: `JsonToken` that is most closely associated with the node type asToken() Method that can be used for efficient type detection when using stream abstraction for traversing nodes.
public TreeNode	Returns: Node that matches given JSON Pointer, if any: if no match exists, will return a "missing" node (for which `TreeNode#isMissingNode()` returns `true`). at(JsonPointer `JsonPointer` expression for descendant node to return ptr) Method for locating node specified by given JSON pointer instances.
public TreeNode	Returns: Node that matches given JSON Pointer, if any: if no match exists, will return a "missing" node (for which `TreeNode#isMissingNode()` returns `true`). at(String Expression to compile as a `JsonPointer` instance jsonPointerExpression) Convenience method that is functionally equivalent to: return at(JsonPointer.valueOf(jsonPointerExpression));
public Iterator<String>	Returns: An iterator for traversing names of all fields this Object node has (if Object node); empty `Iterator` otherwise (never `null`). fieldNames() Method for accessing names of all fields for this node, iff this node is an Object node.
public TreeNode	Returns: Node that represent value of the specified field, if this node is an Object and has value for the specified field; `null` otherwise. get(String Name of the field (of Object node) to access fieldName) Method for accessing value of the specified field of an object node.
public TreeNode	Returns: Node that represent value of the specified element, if this node is an array and has specified element; `null` otherwise. get(int Index of the Array node element to access index) Method for accessing value of the specified element of an array node.
public boolean	Returns: `True` for Array nodes, `false` for everything else isArray() Method that returns true if this node is an Array node, false otherwise.
public boolean	Returns: `True` for Array and Object nodes, `false` otherwise isContainerNode() Method that returns true for container nodes: Arrays and Objects.
public boolean	Returns: `True` if this node represents a "missing" node 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.
public boolean	Returns: `True` for Object nodes, `false` for everything else isObject() Method that returns true if this node is an Object node, false otherwise.
public boolean	Returns: True if this node is considered a value node; something that represents either a scalar value or explicit `null` isValueNode() Method that returns true for all value nodes: ones that are not containers, and that do not represent "missing" nodes in the path.
public JsonParser.NumberType	Returns: Type of number contained, if any; or null if node does not contain numeric value. numberType() If this node is a numeric type (as per `JsonToken#isNumeric`), returns native type that node uses to store the numeric value; otherwise returns null.
public TreeNode	Returns: Node that represent value of the specified field, if this node is an object and has value for the specified field; otherwise "missing node" is returned. path(String Name of the field (of Object node) to access fieldName) Method for accessing value of the specified field of an object node.
public TreeNode	Returns: Node that represent value of the specified element, if this node is an array and has specified element; otherwise "missing node" is returned. path(int Index of the Array node element to access index) Method for accessing value of the specified element of an array node.
public int	Returns: For non-container nodes returns 0; for arrays number of contained elements, and for objects number of fields. size() Method that returns number of child nodes this node contains: for Array nodes, number of child elements, for Object nodes, number of fields, and for all other nodes 0.
public JsonParser	Returns: `JsonParser` that will stream over contents of this node traverse() Method for constructing a `JsonParser` instance for iterating over contents of the tree that this node is root of.
public JsonParser	Returns: `JsonParser` that will stream over contents of this node traverse(ObjectCodec `ObjectCodec` to associate with parser constructed codec) Same as `traverse()`, but additionally passes `com.fasterxml.jackson.core.ObjectCodec` to use if `JsonParser#readValueAs(Class)` is used (otherwise caller must call `JsonParser#setCodec` on response explicitly).

Method Detail

asToken back to summary

asToken	back to summary
public 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) Returns:JsonToken `JsonToken` that is most closely associated with the node type

public 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)

Returns:JsonToken: JsonToken that is most closely associated with the node type

at back to summary

at	back to summary
public TreeNode at(JsonPointer ptr) Method for locating node specified by given JSON pointer instances. Method will never return null; if no matching node exists, will return a node for which `TreeNode#isMissingNode()` returns true. Parameters ptr:JsonPointer `JsonPointer` expression for descendant node to return Returns:TreeNode Node that matches given JSON Pointer, if any: if no match exists, will return a "missing" node (for which `TreeNode#isMissingNode()` returns `true`). Since 2.3

public TreeNode at(JsonPointer ptr)

Method for locating node specified by given JSON pointer instances. Method will never return null; if no matching node exists, will return a node for which TreeNode#isMissingNode() returns true.

Parameters

ptr:JsonPointer: JsonPointer expression for descendant node to return

Returns:TreeNode

Node that matches given JSON Pointer, if any: if no match exists, will return a "missing" node (for which TreeNode#isMissingNode() returns true).

Since

2.3

at back to summary

at	back to summary
public TreeNode at(String jsonPointerExpression) throws IllegalArgumentException Convenience method that is functionally equivalent to: return at(JsonPointer.valueOf(jsonPointerExpression)); Note that if the same expression is used often, it is preferable to construct `JsonPointer` instance once and reuse it: this method will not perform any caching of compiled expressions. Parameters jsonPointerExpression:String Expression to compile as a `JsonPointer` instance Returns:TreeNode Node that matches given JSON Pointer, if any: if no match exists, will return a "missing" node (for which `TreeNode#isMissingNode()` returns `true`). Since 2.3

public TreeNode at(String jsonPointerExpression) throws IllegalArgumentException

Convenience method that is functionally equivalent to:

   return at(JsonPointer.valueOf(jsonPointerExpression));

Note that if the same expression is used often, it is preferable to construct JsonPointer instance once and reuse it: this method will not perform any caching of compiled expressions.

Parameters

jsonPointerExpression:String: Expression to compile as a JsonPointer instance

Returns:TreeNode

Node that matches given JSON Pointer, if any: if no match exists, will return a "missing" node (for which TreeNode#isMissingNode() returns true).

Since

2.3

fieldNames back to summary

fieldNames	back to summary
public Iterator<String> fieldNames() Method for accessing names of all fields for this node, iff this node is an Object node. Number of field names accessible will be `size`. Returns:Iterator<String> An iterator for traversing names of all fields this Object node has (if Object node); empty `Iterator` otherwise (never `null`). Since 2.2

public Iterator<String> fieldNames()

Method for accessing names of all fields for this node, iff this node is an Object node. Number of field names accessible will be size.

Returns:Iterator<String>: An iterator for traversing names of all fields this Object node has (if Object node); empty Iterator otherwise (never null).
Since: 2.2

get back to summary

get	back to summary
public TreeNode get(String fieldName) Method for accessing value of the specified field of an object node. If this node is not an object (or it does not have a value for specified field name), or if there is no field with such name, null is returned. Note handling of explicit null values may vary between implementations; some trees may retain explicit nulls, others not. Parameters fieldName:String Name of the field (of Object node) to access Returns:TreeNode Node that represent value of the specified field, if this node is an Object and has value for the specified field; `null` otherwise. Since 2.2

public TreeNode get(String fieldName)

Method for accessing value of the specified field of an object node. If this node is not an object (or it does not have a value for specified field name), or if there is no field with such name, null is returned.

Note

handling of explicit null values may vary between implementations; some trees may retain explicit nulls, others not.

Parameters

fieldName:String: Name of the field (of Object node) to access

Returns:TreeNode

Node that represent value of the specified field, if this node is an Object and has value for the specified field; null otherwise.

Since

2.2

get back to summary

get	back to summary
public TreeNode get(int index) Method for accessing value of the specified element of an array node. For other nodes, null is 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. Parameters index:int Index of the Array node element to access Returns:TreeNode Node that represent value of the specified element, if this node is an array and has specified element; `null` otherwise. Since 2.2

public TreeNode get(int index)

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

Parameters

index:int: Index of the Array node element to access

Returns:TreeNode

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

Since

2.2

isArray back to summary

isArray	back to summary
public boolean isArray() Method that returns true if this node is an Array node, false otherwise. Note that if true is returned, `isContainerNode` must also return true. Returns:boolean `True` for Array nodes, `false` for everything else Since 2.2

public boolean isArray()

Method that returns true if this node is an Array node, false otherwise. Note that if true is returned, isContainerNode must also return true.

Returns:boolean: True for Array nodes, false for everything else
Since: 2.2

isContainerNode back to summary

isContainerNode	back to summary
public boolean isContainerNode() Method that returns true for container nodes: Arrays and Objects. Note one and only one of methods `isValueNode`, `isContainerNode` and `isMissingNode` ever returns true for any given node. Returns:boolean `True` for Array and Object nodes, `false` otherwise Since 2.2

public boolean isContainerNode()

Method that returns true for container nodes: Arrays and Objects.

Note

one and only one of methods isValueNode, isContainerNode and isMissingNode ever returns true for any given node.

Returns:boolean: True for Array and Object nodes, false otherwise
Since: 2.2

isMissingNode back to summary

isMissingNode	back to summary
public 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. Note one and only one of methods `isValueNode`, `isContainerNode` and `isMissingNode` ever returns true for any given node. Returns:boolean `True` if this node represents a "missing" node Since 2.2

public 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.

Note

one and only one of methods isValueNode, isContainerNode and isMissingNode ever returns true for any given node.

Returns:boolean: True if this node represents a "missing" node
Since: 2.2

isObject back to summary

isObject	back to summary
public boolean isObject() Method that returns true if this node is an Object node, false otherwise. Note that if true is returned, `isContainerNode` must also return true. Returns:boolean `True` for Object nodes, `false` for everything else Since 2.2

public boolean isObject()

Method that returns true if this node is an Object node, false otherwise. Note that if true is returned, isContainerNode must also return true.

Returns:boolean: True for Object nodes, false for everything else
Since: 2.2

isValueNode back to summary

isValueNode	back to summary
public boolean isValueNode() Method that returns true for all value nodes: ones that are not containers, and that do not represent "missing" nodes in the path. Such value nodes represent String, Number, Boolean and null values from JSON. Note one and only one of methods `isValueNode`, `isContainerNode` and `isMissingNode` ever returns true for any given node. Returns:boolean True if this node is considered a value node; something that represents either a scalar value or explicit `null` Since 2.2

public boolean isValueNode()

Method that returns true for all value nodes: ones that are not containers, and that do not represent "missing" nodes in the path. Such value nodes represent String, Number, Boolean and null values from JSON.

Note

one and only one of methods isValueNode, isContainerNode and isMissingNode ever returns true for any given node.

Returns:boolean: True if this node is considered a value node; something that represents either a scalar value or explicit null
Since: 2.2

numberType back to summary

numberType	back to summary
public JsonParser.NumberType numberType() If this node is a numeric type (as per `JsonToken#isNumeric`), returns native type that node uses to store the numeric value; otherwise returns null. Returns:JsonParser.NumberType Type of number contained, if any; or null if node does not contain numeric value.

public JsonParser.NumberType numberType()

If this node is a numeric type (as per JsonToken#isNumeric), returns native type that node uses to store the numeric value; otherwise returns null.

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

path back to summary

path	back to summary
public TreeNode path(String fieldName) Method for accessing value of the specified field of an object node. For other nodes, a "missing node" (virtual node for which `isMissingNode` returns true) is returned. Parameters fieldName:String Name of the field (of Object node) to access Returns:TreeNode Node that represent value of the specified field, if this node is an object and has value for the specified field; otherwise "missing node" is returned. Since 2.2

public TreeNode path(String fieldName)

Method for accessing value of the specified field of an object node. For other nodes, a "missing node" (virtual node for which isMissingNode returns true) is returned.

Parameters

fieldName:String: Name of the field (of Object node) to access

Returns:TreeNode

Node that represent value of the specified field, if this node is an object and has value for the specified field; otherwise "missing node" is returned.

Since

2.2

path back to summary

path	back to summary
public TreeNode path(int index) Method for accessing value of the specified element of an array node. For other nodes, a "missing node" (virtual node for which `isMissingNode` returns true) is 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()`, "missing node" is returned; no exception is thrown for any index. Parameters index:int Index of the Array node element to access Returns:TreeNode Node that represent value of the specified element, if this node is an array and has specified element; otherwise "missing node" is returned. Since 2.2

public TreeNode path(int index)

Method for accessing value of the specified element of an array node. For other nodes, a "missing node" (virtual node for which isMissingNode returns true) is 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(), "missing node" is returned; no exception is thrown for any index.

Parameters

index:int: Index of the Array node element to access

Returns:TreeNode

Node that represent value of the specified element, if this node is an array and has specified element; otherwise "missing node" is returned.

Since

2.2

size	back to summary
public int size() Method that returns number of child nodes this node contains: for Array nodes, number of child elements, for Object nodes, number of fields, and for all other nodes 0. Returns:int For non-container nodes returns 0; for arrays number of contained elements, and for objects number of fields. Since 2.2

size

back to summary

public int size()

Method that returns number of child nodes this node contains: for Array nodes, number of child elements, for Object nodes, number of fields, and for all other nodes 0.

Returns:int: For non-container nodes returns 0; for arrays number of contained elements, and for objects number of fields.
Since: 2.2

traverse back to summary

traverse	back to summary
public JsonParser traverse() 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`). It is often better to call `traverse(ObjectCodec)` to pass the codec explicitly. Returns:JsonParser `JsonParser` that will stream over contents of this node

public JsonParser traverse()

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). It is often better to call traverse(ObjectCodec) to pass the codec explicitly.

Returns:JsonParser: JsonParser that will stream over contents of this node

traverse back to summary

traverse	back to summary
public JsonParser traverse(ObjectCodec codec) Same as `traverse()`, but additionally passes `com.fasterxml.jackson.core.ObjectCodec` to use if `JsonParser#readValueAs(Class)` is used (otherwise caller must call `JsonParser#setCodec` 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()`. Parameters codec:ObjectCodec `ObjectCodec` to associate with parser constructed Returns:JsonParser `JsonParser` that will stream over contents of this node Since 2.1

public JsonParser traverse(ObjectCodec codec)

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

Note

Parameters

codec:ObjectCodec: ObjectCodec to associate with parser constructed

Returns:JsonParser

JsonParser that will stream over contents of this node

Since

2.1

public Interface TreeNode

Method Summary

Method Detail