JsonNode (jackson-databind 2.13.0 API)

java.lang.Object
- com.fasterxml.jackson.databind.JsonSerializable.Base
- - com.fasterxml.jackson.databind.JsonNode

All Implemented Interfaces:

TreeNode, JsonSerializable, Iterable<JsonNode>

Direct Known Subclasses:

BaseJsonNode
```
public abstract class JsonNode
extends JsonSerializable.Base
implements TreeNode, Iterable<JsonNode>
```
Base class for all JSON nodes, which form the basis of JSON Tree Model that Jackson implements. One way to think of these nodes is to consider them similar to DOM nodes in XML DOM trees.
As a general design rule, most accessors ("getters") are included in this base class, to allow for traversing structure without type casts. Most mutators, however, need to be accessed through specific sub-classes (such as ObjectNode and ArrayNode). This seems sensible because proper type information is generally available when building or modifying trees, but less often when reading a tree (newly built from parsed JSON content).
Actual concrete sub-classes can be found from package com.fasterxml.jackson.databind.node.
Note that it is possible to "read" from nodes, using method TreeNode.traverse(ObjectCodec), which will result in a JsonParser being constructed. This can be used for (relatively) efficient conversations between different representations; and it is what core databind uses for methods like ObjectMapper.treeToValue(TreeNode, Class) and ObjectMapper.treeAsTokens(TreeNode)

Nested Class Summary
- Nested classes/interfaces inherited from interface com.fasterxml.jackson.databind.JsonSerializable
  JsonSerializable.Base

Constructor Summary

Constructors
Modifier Constructor and Description

protected JsonNode()

Constructors
Modifier	Constructor and Description
`protected`	`JsonNode()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected abstract 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 <T> T`	`_reportRequiredViolation(String msgTemplate, Object... args)` Helper method that throws `IllegalArgumentException` as a result of violating "required-constraint" for this node (for `required(java.lang.String)` or related methods).
`protected <T extends JsonNode> T`	`_this()`
`boolean`	`asBoolean()` Method that will try to convert value of this node to a Java boolean.
`boolean`	`asBoolean(boolean defaultValue)` Method that will try to convert value of this node to a Java boolean.
`double`	`asDouble()` Method that will try to convert value of this node to a Java double.
`double`	`asDouble(double defaultValue)` Method that will try to convert value of this node to a Java double.
`int`	`asInt()` Method that will try to convert value of this node to a Java int.
`int`	`asInt(int defaultValue)` Method that will try to convert value of this node to a Java int.
`long`	`asLong()` Method that will try to convert value of this node to a Java long.
`long`	`asLong(long defaultValue)` Method that will try to convert value of this node to a Java long.
`abstract String`	`asText()` Method that will return a valid String representation of the container value, if the node is a value node (method `isValueNode()` returns true), otherwise empty String.
`String`	`asText(String defaultValue)` Method similar to `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.
`JsonNode`	`at(JsonPointer ptr)` Method for locating node specified by given JSON pointer instances.
`JsonNode`	`at(String jsonPtrExpr)` Convenience method that is functionally equivalent to:
`BigInteger`	`bigIntegerValue()` Returns integer value for this node (as `BigDecimal`), if and only if this node is numeric (`isNumber()` returns true).
`byte[]`	`binaryValue()` Method to use for accessing binary content of binary nodes (nodes for which `isBinary()` returns true); or for Text Nodes (ones for which `textValue()` returns non-null value), to read decoded base64 data.
`boolean`	`booleanValue()` Method to use for accessing JSON boolean values (value literals 'true' and 'false').
`boolean`	`canConvertToExactIntegral()` Method that can be used to check whether contained value is numeric (returns true for `isNumber()`) and can be losslessly converted to integral number (specifically, `BigInteger` but potentially others, see `canConvertToInt()` and `canConvertToInt()`).
`boolean`	`canConvertToInt()` Method that can be used to check whether this node is a numeric node (`isNumber()` would return true) AND its value fits within Java's 32-bit signed integer type, `int`.
`boolean`	`canConvertToLong()` Method that can be used to check whether this node is a numeric node (`isNumber()` would return true) AND its value fits within Java's 64-bit signed integer type, `long`.
`BigDecimal`	`decimalValue()` Returns floating point value for this node (as `BigDecimal`), if and only if this node is numeric (`isNumber()` returns true).
`abstract <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.
`double`	`doubleValue()` Returns 64-bit floating point (double) value for this node, if and only if this node is numeric (`isNumber()` returns true).
`Iterator<JsonNode>`	`elements()` Method for accessing all value nodes of this Node, iff this node is a JSON Array or Object node.
`boolean`	`equals(Comparator<JsonNode> comparator, JsonNode other)` Entry method for invoking customizable comparison, using passed-in `Comparator` object.
`abstract boolean`	`equals(Object o)` Equality for node objects is defined as full (deep) value equality.
`Iterator<String>`	`fieldNames()`
`Iterator<Map.Entry<String,JsonNode>>`	`fields()`
`abstract 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)` Method for finding a JSON Object that contains specified field, within this node or its descendants.
`abstract List<JsonNode>`	`findParents(String fieldName, List<JsonNode> foundSoFar)`
`abstract JsonNode`	`findPath(String fieldName)` Method similar to `findValue(java.lang.String)`, but that will return a "missing node" instead of null if no field is found.
`abstract JsonNode`	`findValue(String fieldName)` Method for finding a JSON Object field with specified name in this node or its child nodes, and returning value it has.
`List<JsonNode>`	`findValues(String fieldName)` Method for finding JSON Object fields with specified name, and returning found ones as a List.
`abstract List<JsonNode>`	`findValues(String fieldName, List<JsonNode> foundSoFar)`
`List<String>`	`findValuesAsText(String fieldName)` Similar to `findValues(java.lang.String)`, but will additionally convert values into Strings, calling `asText()`.
`abstract List<String>`	`findValuesAsText(String fieldName, List<String> foundSoFar)`
`float`	`floatValue()` Returns 32-bit floating value for this node, if and only if this node is numeric (`isNumber()` returns true).
`abstract JsonNode`	`get(int index)` Method for accessing value of the specified element of an array node.
`JsonNode`	`get(String fieldName)` Method for accessing value of the specified field of an object node.
`abstract JsonNodeType`	`getNodeType()` Return the type of this node
`boolean`	`has(int index)` Method that allows checking whether this node is JSON Array node and contains a value for specified index If this is the case (including case of specified indexing having null as value), returns true; otherwise returns false.
`boolean`	`has(String fieldName)` Method that allows checking whether this node is JSON Object node and contains value for specified property.
`boolean`	`hasNonNull(int index)` Method that is similar to `has(int)`, but that will return `false` for explicitly added nulls.
`boolean`	`hasNonNull(String fieldName)` Method that is similar to `has(String)`, but that will return `false` for explicitly added nulls.
`int`	`intValue()` Returns integer value for this node, if and only if this node is numeric (`isNumber()` returns true).
`boolean`	`isArray()`
`boolean`	`isBigDecimal()`
`boolean`	`isBigInteger()`
`boolean`	`isBinary()` Method that can be used to check if this node represents binary data (Base64 encoded).
`boolean`	`isBoolean()` Method that can be used to check if this node was created from JSON boolean value (literals "true" and "false").
`boolean`	`isContainerNode()`
`boolean`	`isDouble()`
`boolean`	`isEmpty()` Convenience method that is functionally same as:
`boolean`	`isFloat()`
`boolean`	`isFloatingPointNumber()`
`boolean`	`isInt()` Method that can be used to check whether contained value is a number represented as Java `int`.
`boolean`	`isIntegralNumber()`
`boolean`	`isLong()` Method that can be used to check whether contained value is a number represented as Java `long`.
`boolean`	`isMissingNode()`
`boolean`	`isNull()` Method that can be used to check if this node was created from JSON literal null value.
`boolean`	`isNumber()`
`boolean`	`isObject()`
`boolean`	`isPojo()` Method that can be used to check if the node is a wrapper for a POJO ("Plain Old Java Object" aka "bean".
`boolean`	`isShort()` Method that can be used to check whether contained value is a number represented as Java `short`.
`boolean`	`isTextual()` Method that checks whether this node represents basic JSON String value.
`boolean`	`isValueNode()`
`Iterator<JsonNode>`	`iterator()` Same as calling `elements()`; implemented so that convenience "for-each" loop can be used for looping over elements of JSON Array constructs.
`long`	`longValue()` Returns 64-bit long value for this node, if and only if this node is numeric (`isNumber()` returns true).
`Number`	`numberValue()` Returns numeric value for this node, if and only if this node is numeric (`isNumber()` returns true); otherwise returns null
`abstract JsonNode`	`path(int index)` This method is similar to `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 `isMissingNode()`) will be returned.
`abstract JsonNode`	`path(String fieldName)` This method is similar to `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 `isMissingNode()`) will be returned.
`<T extends JsonNode> T`	`require()` Method that may be called to verify that `this` node is NOT so-called "missing node": that is, one for which `isMissingNode()` returns `true`.
`JsonNode`	`required(int index)` Method is functionally equivalent to `path(index).required()` and can be used to check that this node is an `ArrayNode` (that is, represents JSON Array value) and has value for specified `index` (but note that value may be explicit JSON null value).
`JsonNode`	`required(String propertyName)` Method is functionally equivalent to `path(fieldName).required()` and can be used to check that this node is an `ObjectNode` (that is, represents JSON Object value) and has value for specified property with key `fieldName` (but note that value may be explicit JSON null value).
`JsonNode`	`requiredAt(JsonPointer path)` Method is functionally equivalent to `at(path).required()` and can be used to check that there is an actual value node at specified `JsonPointer` starting from `this` node (but note that value may be explicit JSON null value).
`JsonNode`	`requiredAt(String pathExpr)` Method is functionally equivalent to `at(pathExpr).required()` and can be used to check that there is an actual value node at specified `JsonPointer` starting from `this` node (but note that value may be explicit JSON null value).
`<T extends JsonNode> T`	`requireNonNull()` Method that may be called to verify that `this` node is neither so-called "missing node" (that is, one for which `isMissingNode()` returns `true`) nor "null node" (one for which `isNull()` returns `true`).
`short`	`shortValue()` Returns 16-bit short value for this node, if and only if this node is numeric (`isNumber()` returns true).
`int`	`size()`
`String`	`textValue()` Method to use for accessing String values.
`String`	`toPrettyString()` Alternative to `toString()` that will serialize this node using Jackson default pretty-printer.
`abstract String`	`toString()` Method that will produce (as of Jackson 2.10) valid JSON using default settings of databind, as String.
`<T extends JsonNode> T`	`with(String propertyName)` Method that can be called on Object nodes, to access a property that has Object value; or if no such property exists, to create, add and return such Object node.
`<T extends JsonNode> T`	`withArray(String propertyName)` Method that can be called on Object nodes, to access a property that has `Array` value; or if no such property exists, to create, add and return such Array node.

Methods inherited from class com.fasterxml.jackson.databind.JsonSerializable.Base
isEmpty

Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.fasterxml.jackson.core.TreeNode
asToken, numberType, traverse, traverse

Methods inherited from interface java.lang.Iterable
forEach, spliterator

Methods inherited from interface com.fasterxml.jackson.databind.JsonSerializable
serialize, serializeWithType

- Constructor Detail
  - JsonNode
```
protected JsonNode()
```
- Method Detail
  - deepCopy
```
public abstract <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. 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.
    
    Returns:
    
    Node that is either a copy of this node (and all non-leaf children); or, for immutable leaf nodes, node itself.
    
    Since:
    
    2.0
  - size
```
public int size()
```
    Specified by:
    
    size in interface TreeNode
  - isEmpty
```
public boolean isEmpty()
```
    Convenience method that is functionally same as:
```
    size() == 0
```
    for all node types.
    Since:
    
    2.10
  - isValueNode
```
public final boolean isValueNode()
```
    Specified by:
    
    isValueNode in interface TreeNode
  - isContainerNode
```
public final boolean isContainerNode()
```
    Specified by:
    
    isContainerNode in interface TreeNode
  - isMissingNode
```
public boolean isMissingNode()
```
    Specified by:
    
    isMissingNode in interface TreeNode
  - isArray
```
public boolean isArray()
```
    Specified by:
    
    isArray in interface TreeNode
  - isObject
```
public boolean isObject()
```
    Specified by:
    
    isObject in interface TreeNode
  - get
```
public abstract JsonNode get(int index)
```
    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
    
    Returns:
    
    Node that represent value of the specified element, if this node is an array and has specified element. Null otherwise.
  - get
```
public JsonNode 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: if the property 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
    
    Returns:
    
    Node that represent value of the specified field, if this node is an object and has value for the specified field. Null otherwise.
  - path
```
public abstract JsonNode path(String fieldName)
```
    This method is similar to 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 isMissingNode()) will be returned. This allows for convenient and safe chained access via path calls.
    
    Specified by:
    
    path in interface TreeNode
  - path
```
public abstract JsonNode path(int index)
```
    This method is similar to 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 isMissingNode()) will be returned. This allows for convenient and safe chained access via path calls.
    
    Specified by:
    
    path in interface TreeNode
  - fieldNames
```
public Iterator<String> fieldNames()
```
    Specified by:
    
    fieldNames in interface TreeNode
  - at
```
public final JsonNode 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 isMissingNode() returns true.
    
    Specified by:
    
    at in interface TreeNode
    
    Returns:
    
    Node that matches given JSON Pointer: if no match exists, will return a node for which isMissingNode() returns true.
    
    Since:
    
    2.3
  - at
```
public final JsonNode at(String jsonPtrExpr)
```
    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.
    Specified by:
    
    at in interface TreeNode
    
    Parameters:
    
    jsonPtrExpr - Expression to compile as a JsonPointer instance
    
    Returns:
    
    Node that matches given JSON Pointer: if no match exists, will return a node for which TreeNode.isMissingNode() returns true.
    
    Since:
    
    2.3
  - _at
```
protected abstract 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.
    
    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)
  - getNodeType
```
public abstract JsonNodeType getNodeType()
```
    Return the type of this node
    
    Returns:
    
    the node type as a JsonNodeType enum value
    
    Since:
    
    2.2
  - isPojo
```
public final boolean isPojo()
```
    Method that can be used to check if the node is a wrapper for a POJO ("Plain Old Java Object" aka "bean". Returns true only for instances of POJONode.
    
    Returns:
    
    True if this node wraps a POJO
  - isNumber
```
public final boolean isNumber()
```
    Returns:
    
    True if this node represents a numeric JSON value
  - isIntegralNumber
```
public boolean isIntegralNumber()
```
    Returns:
    
    True if this node represents an integral (integer) numeric JSON value
  - isFloatingPointNumber
```
public boolean isFloatingPointNumber()
```
    Returns:
    
    True if this node represents a non-integral numeric JSON value
  - isShort
```
public boolean isShort()
```
    Method that can be used to check whether contained value is a number represented as Java short. Note, however, that even if this method returns false, it is possible that conversion would be possible from other numeric types -- to check if this is possible, use canConvertToInt() instead.
    
    Returns:
    
    True if the value contained by this node is stored as Java short
  - isInt
```
public boolean isInt()
```
    Method that can be used to check whether contained value is a number represented as Java int. Note, however, that even if this method returns false, it is possible that conversion would be possible from other numeric types -- to check if this is possible, use canConvertToInt() instead.
    
    Returns:
    
    True if the value contained by this node is stored as Java int
  - isLong
```
public boolean isLong()
```
    Method that can be used to check whether contained value is a number represented as Java long. Note, however, that even if this method returns false, it is possible that conversion would be possible from other numeric types -- to check if this is possible, use canConvertToLong() instead.
    
    Returns:
    
    True if the value contained by this node is stored as Java long
  - isFloat
```
public boolean isFloat()
```
    Since:
    
    2.2
  - isDouble
```
public boolean isDouble()
```
  - isBigDecimal
```
public boolean isBigDecimal()
```
  - isBigInteger
```
public boolean isBigInteger()
```
  - isTextual
```
public final boolean isTextual()
```
    Method that checks whether this node represents basic JSON String value.
  - isBoolean
```
public final boolean isBoolean()
```
    Method that can be used to check if this node was created from JSON boolean value (literals "true" and "false").
  - isNull
```
public final boolean isNull()
```
    Method that can be used to check if this node was created from JSON literal null value.
  - isBinary
```
public final boolean isBinary()
```
    Method that can be used to check if this node represents binary data (Base64 encoded). Although this will be externally written as JSON String value, isTextual() will return false if this method returns true.
    
    Returns:
    
    True if this node represents base64 encoded binary data
  - canConvertToInt
```
public boolean canConvertToInt()
```
    Method that can be used to check whether this node is a numeric node (isNumber() would return true) AND its value fits within Java's 32-bit signed integer type, int. Note that floating-point numbers are convertible if the integral part fits without overflow (as per standard Java coercion rules)
    NOTE: this method does not consider possible value type conversion from JSON String into Number; so even if this method returns false, it is possible that asInt() could still succeed if node is a JSON String representing integral number, or boolean.
    
    Since:
    
    2.0
  - canConvertToLong
```
public boolean canConvertToLong()
```
    Method that can be used to check whether this node is a numeric node (isNumber() would return true) AND its value fits within Java's 64-bit signed integer type, long. Note that floating-point numbers are convertible if the integral part fits without overflow (as per standard Java coercion rules)
    NOTE: this method does not consider possible value type conversion from JSON String into Number; so even if this method returns false, it is possible that asLong() could still succeed if node is a JSON String representing integral number, or boolean.
    
    Since:
    
    2.0
  - canConvertToExactIntegral
```
public boolean canConvertToExactIntegral()
```
    Method that can be used to check whether contained value is numeric (returns true for isNumber()) and can be losslessly converted to integral number (specifically, BigInteger but potentially others, see canConvertToInt() and canConvertToInt()). Latter part allows floating-point numbers (for which isFloatingPointNumber() returns true) that do not have fractional part. Note that "not-a-number" values of double and float will return false as they can not be converted to matching integral representations.
    
    Returns:
    
    True if the value is an actual number with no fractional part; false for non-numeric types, NaN representations of floating-point numbers, and floating-point numbers with fractional part.
    
    Since:
    
    2.12
  - textValue
```
public String textValue()
```
    Method to use for accessing String values. Does NOT do any conversions for non-String value nodes; for non-String values (ones for which isTextual() returns false) null will be returned. For String values, null is never returned (but empty Strings may be)
    
    Returns:
    
    Textual value this node contains, iff it is a textual JSON node (comes from JSON String value entry)
  - binaryValue
```
public byte[] binaryValue()
                   throws IOException
```
    Method to use for accessing binary content of binary nodes (nodes for which isBinary() returns true); or for Text Nodes (ones for which textValue() returns non-null value), to read decoded base64 data. For other types of nodes, returns null.
    
    Returns:
    
    Binary data this node contains, iff it is a binary node; null otherwise
    
    Throws:
    
    IOException
  - booleanValue
```
public boolean booleanValue()
```
    Method to use for accessing JSON boolean values (value literals 'true' and 'false'). For other types, always returns false.
    
    Returns:
    
    Textual value this node contains, iff it is a textual json node (comes from JSON String value entry)
  - numberValue
```
public Number numberValue()
```
    Returns numeric value for this node, if and only if this node is numeric (isNumber() returns true); otherwise returns null
    
    Returns:
    
    Number value this node contains, if any (null for non-number nodes).
  - shortValue
```
public short shortValue()
```
    Returns 16-bit short value for this node, if and only if this node is numeric (isNumber() returns true). For other types returns 0. For floating-point numbers, value is truncated using default Java coercion, similar to how cast from double to short operates.
    
    Returns:
    
    Short value this node contains, if any; 0 for non-number nodes.
  - intValue
```
public int intValue()
```
    Returns integer value for this node, if and only if this node is numeric (isNumber() returns true). For other types returns 0. For floating-point numbers, value is truncated using default Java coercion, similar to how cast from double to int operates.
    
    Returns:
    
    Integer value this node contains, if any; 0 for non-number nodes.
  - longValue
```
public long longValue()
```
    Returns 64-bit long value for this node, if and only if this node is numeric (isNumber() returns true). For other types returns 0. For floating-point numbers, value is truncated using default Java coercion, similar to how cast from double to long operates.
    
    Returns:
    
    Long value this node contains, if any; 0 for non-number nodes.
  - floatValue
```
public float floatValue()
```
    Returns 32-bit floating value for this node, if and only if this node is numeric (isNumber() returns true). For other types returns 0.0. For integer values, conversion is done using coercion; this means that an overflow is possible for `long` values
    
    Returns:
    
    32-bit float value this node contains, if any; 0.0 for non-number nodes.
    
    Since:
    
    2.2
  - doubleValue
```
public double doubleValue()
```
    Returns 64-bit floating point (double) value for this node, if and only if this node is numeric (isNumber() returns true). For other types returns 0.0. For integer values, conversion is done using coercion; this may result in overflows with BigInteger values.
    
    Returns:
    
    64-bit double value this node contains, if any; 0.0 for non-number nodes.
    
    Since:
    
    2.2
  - decimalValue
```
public BigDecimal decimalValue()
```
    Returns floating point value for this node (as BigDecimal), if and only if this node is numeric (isNumber() returns true). For other types returns BigDecimal.ZERO.
    
    Returns:
    
    BigDecimal value this node contains, if numeric node; BigDecimal.ZERO for non-number nodes.
  - bigIntegerValue
```
public BigInteger bigIntegerValue()
```
    Returns integer value for this node (as BigDecimal), if and only if this node is numeric (isNumber() returns true). For other types returns BigInteger.ZERO.
    
    Returns:
    
    BigInteger value this node contains, if numeric node; BigInteger.ZERO for non-number nodes.
  - asText
```
public abstract String asText()
```
    Method that will return a valid String representation of the container value, if the node is a value node (method isValueNode() returns true), otherwise empty String.
  - asText
```
public String asText(String defaultValue)
```
    Method similar to 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.
    
    Since:
    
    2.4
  - asInt
```
public int asInt()
```
    Method that will try to convert value of this node to a Java int. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.
    If representation cannot be converted to an int (including structured types like Objects and Arrays), default value of 0 will be returned; no exceptions are thrown.
  - asInt
```
public int asInt(int defaultValue)
```
    Method that will try to convert value of this node to a Java int. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.
    If representation cannot be converted to an int (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
  - asLong
```
public long asLong()
```
    Method that will try to convert value of this node to a Java long. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.
    If representation cannot be converted to a long (including structured types like Objects and Arrays), default value of 0 will be returned; no exceptions are thrown.
  - asLong
```
public long asLong(long defaultValue)
```
    Method that will try to convert value of this node to a Java long. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.
    If representation cannot be converted to a long (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
  - asDouble
```
public double asDouble()
```
    Method that will try to convert value of this node to a Java double. Numbers are coerced using default Java rules; booleans convert to 0.0 (false) and 1.0 (true), and Strings are parsed using default Java language integer parsing rules.
    If representation cannot be converted to an int (including structured types like Objects and Arrays), default value of 0.0 will be returned; no exceptions are thrown.
  - asDouble
```
public double asDouble(double defaultValue)
```
    Method that will try to convert value of this node to a Java double. Numbers are coerced using default Java rules; booleans convert to 0.0 (false) and 1.0 (true), and Strings are parsed using default Java language integer parsing rules.
    If representation cannot be converted to an int (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
  - asBoolean
```
public boolean asBoolean()
```
    Method that will try to convert value of this node to a Java boolean. JSON booleans map naturally; integer numbers other than 0 map to true, and 0 maps to false and Strings 'true' and 'false' map to corresponding values.
    If representation cannot be converted to a boolean value (including structured types like Objects and Arrays), default value of false will be returned; no exceptions are thrown.
  - asBoolean
```
public boolean asBoolean(boolean defaultValue)
```
    Method that will try to convert value of this node to a Java boolean. JSON booleans map naturally; integer numbers other than 0 map to true, and 0 maps to false and Strings 'true' and 'false' map to corresponding values.
    If representation cannot be converted to a boolean value (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
  - require
```
public <T extends JsonNode> T require()
                               throws IllegalArgumentException
```
    Method that may be called to verify that this node is NOT so-called "missing node": that is, one for which isMissingNode() returns true. If not missing node, this is returned to allow chaining; otherwise IllegalArgumentException is thrown.
    
    Returns:
    
    this node to allow chaining
    
    Throws:
    
    IllegalArgumentException - if this node is "missing node"
    
    Since:
    
    2.10
  - requireNonNull
```
public <T extends JsonNode> T requireNonNull()
                                      throws IllegalArgumentException
```
    Method that may be called to verify that this node is neither so-called "missing node" (that is, one for which isMissingNode() returns true) nor "null node" (one for which isNull() returns true). If non-null non-missing node, this is returned to allow chaining; otherwise IllegalArgumentException is thrown.
    
    Returns:
    
    this node to allow chaining
    
    Throws:
    
    IllegalArgumentException - if this node is either "missing node" or "null node"
    
    Since:
    
    2.10
  - required
```
public JsonNode required(String propertyName)
                  throws IllegalArgumentException
```
    Method is functionally equivalent to path(fieldName).required() and can be used to check that this node is an ObjectNode (that is, represents JSON Object value) and has value for specified property with key fieldName (but note that value may be explicit JSON null value). If this node is Object Node and has value for specified property, matching value is returned; otherwise IllegalArgumentException is thrown.
    
    Parameters:
    
    propertyName - Name of property to access
    
    Returns:
    
    Value of the specified property of this Object node
    
    Throws:
    
    IllegalArgumentException - if this node is not an Object node or if it does not have value for specified property
    
    Since:
    
    2.10
  - required
```
public JsonNode required(int index)
                  throws IllegalArgumentException
```
    Method is functionally equivalent to path(index).required() and can be used to check that this node is an ArrayNode (that is, represents JSON Array value) and has value for specified index (but note that value may be explicit JSON null value). If this node is Array Node and has value for specified index, value at index is returned; otherwise IllegalArgumentException is thrown.
    
    Parameters:
    
    index - Index of the value of this Array node to access
    
    Returns:
    
    Value at specified index of this Array node
    
    Throws:
    
    IllegalArgumentException - if this node is not an Array node or if it does not have value for specified index
    
    Since:
    
    2.10
  - requiredAt
```
public JsonNode requiredAt(String pathExpr)
                    throws IllegalArgumentException
```
    Method is functionally equivalent to at(pathExpr).required() and can be used to check that there is an actual value node at specified JsonPointer starting from this node (but note that value may be explicit JSON null value). If such value node exists it is returned; otherwise IllegalArgumentException is thrown.
    
    Parameters:
    
    pathExpr - JsonPointer expression (as String) to use for finding value node
    
    Returns:
    
    Matching value node for given expression
    
    Throws:
    
    IllegalArgumentException - if no value node exists at given JSON Pointer path
    
    Since:
    
    2.10
  - requiredAt
```
public final JsonNode requiredAt(JsonPointer path)
                          throws IllegalArgumentException
```
    Method is functionally equivalent to at(path).required() and can be used to check that there is an actual value node at specified JsonPointer starting from this node (but note that value may be explicit JSON null value). If such value node exists it is returned; otherwise IllegalArgumentException is thrown.
    
    Parameters:
    
    path - JsonPointer expression to use for finding value node
    
    Returns:
    
    Matching value node for given expression
    
    Throws:
    
    IllegalArgumentException - if no value node exists at given JSON Pointer path
    
    Since:
    
    2.10
  - has
```
public boolean has(String fieldName)
```
    Method that allows checking whether this node is JSON Object node and contains value for specified property. If this is the case (including properties with explicit null values), returns true; otherwise returns false.
    This method is equivalent to:
```
   node.get(fieldName) != null
```
    (since return value of get() is node, not value node contains)
    NOTE: when explicit null values are added, this method will return true for such properties.
    Parameters:
    
    fieldName - Name of element to check
    
    Returns:
    
    True if this node is a JSON Object node, and has a property entry with specified name (with any value, including null value)
  - has
```
public boolean has(int index)
```
    Method that allows checking whether this node is JSON Array node and contains a value for specified index If this is the case (including case of specified indexing having null as value), returns true; otherwise returns false.
    Note: array element indexes are 0-based.
    This method is equivalent to:
```
   node.get(index) != null
```
    NOTE: this method will return true for explicitly added null values.
    Parameters:
    
    index - Index to check
    
    Returns:
    
    True if this node is a JSON Object node, and has a property entry with specified name (with any value, including null value)
  - hasNonNull
```
public boolean hasNonNull(String fieldName)
```
    Method that is similar to has(String), but that will return false for explicitly added nulls.
    This method is functionally equivalent to:
```
   node.get(fieldName) != null && !node.get(fieldName).isNull()
```
    Since:
    
    2.1
  - hasNonNull
```
public boolean hasNonNull(int index)
```
    Method that is similar to has(int), but that will return false for explicitly added nulls.
    This method is equivalent to:
```
   node.get(index) != null && !node.get(index).isNull()
```
    Since:
    
    2.1
  - iterator
```
public final Iterator<JsonNode> iterator()
```
    Same as calling elements(); implemented so that convenience "for-each" loop can be used for looping over elements of JSON Array constructs.
    
    Specified by:
    
    iterator in interface Iterable<JsonNode>
  - elements
```
public Iterator<JsonNode> elements()
```
    Method for accessing all value nodes of this Node, iff this node is a JSON Array or Object node. In case of Object node, field names (keys) are not included, only values. For other types of nodes, returns empty iterator.
  - fields
```
public Iterator<Map.Entry<String,JsonNode>> fields()
```
    Returns:
    
    Iterator that can be used to traverse all key/value pairs for object nodes; empty iterator (no contents) for other types
  - findValue
```
public abstract JsonNode findValue(String fieldName)
```
    Method for finding a 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.
    
    Parameters:
    
    fieldName - Name of field to look for
    
    Returns:
    
    Value of first matching node found, if any; null if none
  - findValues
```
public final List<JsonNode> findValues(String fieldName)
```
    Method for finding JSON Object fields with specified name, and returning found ones as a List. Note that sub-tree search ends if a field is found, so possible children of result nodes are not included. If no matching fields are found in this node or its descendants, returns an empty List.
    
    Parameters:
    
    fieldName - Name of field to look for
  - findValuesAsText
```
public final List<String> findValuesAsText(String fieldName)
```
    Similar to findValues(java.lang.String), but will additionally convert values into Strings, calling asText().
  - findPath
```
public abstract JsonNode findPath(String fieldName)
```
    Method similar to 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 isMissingNode() returns true; and all value access methods return empty or missing value.
    
    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)
  - findParent
```
public abstract JsonNode findParent(String fieldName)
```
    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.
    
    Parameters:
    
    fieldName - Name of field to look for
    
    Returns:
    
    Value of first matching node found, if any; null if none
  - findParents
```
public final List<JsonNode> findParents(String fieldName)
```
    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.
    
    Parameters:
    
    fieldName - Name of field to look for
    
    Returns:
    
    Value of first matching node found, if any; null if none
  - findValues
```
public abstract List<JsonNode> findValues(String fieldName,
                                          List<JsonNode> foundSoFar)
```
  - findValuesAsText
```
public abstract List<String> findValuesAsText(String fieldName,
                                              List<String> foundSoFar)
```
  - findParents
```
public abstract List<JsonNode> findParents(String fieldName,
                                           List<JsonNode> foundSoFar)
```
  - with
```
public <T extends JsonNode> T with(String propertyName)
```
    Method that can be called on Object nodes, to access a property that has Object value; or if no such property exists, to create, add and return such Object node. If the node method is called on is not Object node, or if property exists and has value that is not Object node, UnsupportedOperationException is thrown
    NOTE: since 2.10 has had co-variant return type
  - withArray
```
public <T extends JsonNode> T withArray(String propertyName)
```
    Method that can be called on Object nodes, to access a property that has Array value; or if no such property exists, to create, add and return such Array node. If the node method is called on is not Object node, or if property exists and has value that is not Array node, UnsupportedOperationException is thrown
    NOTE: since 2.10 has had co-variant return type
  - equals
```
public boolean equals(Comparator<JsonNode> comparator,
                      JsonNode other)
```
    Entry method for invoking customizable comparison, using passed-in Comparator object. Nodes will handle traversal of structured types (arrays, objects), but defer to comparator for scalar value comparisons. If a "natural" Comparator is passed -- one that simply calls equals() on one of arguments, passing the other -- implementation is the same as directly calling equals() on node.
    Default implementation simply delegates to passed in comparator, with this as the first argument, and other as the second argument.
    
    Parameters:
    
    comparator - Object called to compare two scalar JsonNode instances, and return either 0 (are equals) or non-zero (not equal)
    
    Since:
    
    2.6
  - toString
```
public abstract String toString()
```
    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 Object
  - toPrettyString
```
public String toPrettyString()
```
    Alternative to toString() that will serialize this node using Jackson default pretty-printer.
    
    Since:
    
    2.10
  - equals
```
public abstract boolean equals(Object o)
```
    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.
    
    Overrides:
    
    equals in class Object
  - _this
```
protected <T extends JsonNode> T _this()
```
  - _reportRequiredViolation
```
protected <T> T _reportRequiredViolation(String msgTemplate,
                                         Object... args)
```
    Helper method that throws IllegalArgumentException as a result of violating "required-constraint" for this node (for required(java.lang.String) or related methods).

Class JsonNode

Nested Class Summary

Nested classes/interfaces inherited from interface com.fasterxml.jackson.databind.JsonSerializable

Constructor Summary

Method Summary

Methods inherited from class com.fasterxml.jackson.databind.JsonSerializable.Base

Methods inherited from class java.lang.Object

Methods inherited from interface com.fasterxml.jackson.core.TreeNode

Methods inherited from interface java.lang.Iterable

Methods inherited from interface com.fasterxml.jackson.databind.JsonSerializable

Constructor Detail

JsonNode

Method Detail

deepCopy

size

isEmpty

isValueNode

isContainerNode

isMissingNode

isArray

isObject

get

get

path

path

fieldNames

at

at

_at

getNodeType

isPojo

isNumber

isIntegralNumber

isFloatingPointNumber

isShort

isInt

isLong

isFloat

isDouble

isBigDecimal

isBigInteger

isTextual

isBoolean

isNull

isBinary

canConvertToInt

canConvertToLong

canConvertToExactIntegral

textValue

binaryValue

booleanValue

numberValue

shortValue

intValue

longValue

floatValue

doubleValue

decimalValue

bigIntegerValue

asText

asText

asInt

asInt

asLong

asLong

asDouble

asDouble

asBoolean

asBoolean

require

requireNonNull

required

required

requiredAt

requiredAt

has

has

hasNonNull

hasNonNull

iterator