public abstract class JsonNode extends Object implements Iterable<JsonNode>
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 org.codehaus.jackson.node.ObjectNode
and org.codehaus.jackson.node.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
org.codehaus.jackson.node
, which is in 'mapper' jar
(whereas this class is in 'core' jar, since it is declared as
nominal type for operations in ObjectCodec
)
Modifier and Type | Field and Description |
---|---|
protected static List<JsonNode> |
NO_NODES |
protected static List<String> |
NO_STRINGS |
Modifier | Constructor and Description |
---|---|
protected |
JsonNode() |
Modifier and Type | Method and Description |
---|---|
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 valid String representation of
the container value, if the node is a value node
(method
isValueNode() returns true), otherwise
empty String. |
abstract JsonToken |
asToken()
Method that can be used for efficient type detection
when using stream abstraction for traversing nodes.
|
abstract boolean |
equals(Object o)
Equality for node objects is defined as full (deep) value
equality.
|
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 getValueAsText() . |
abstract List<String> |
findValuesAsText(String fieldName,
List<String> foundSoFar) |
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.
|
BigInteger |
getBigIntegerValue() |
byte[] |
getBinaryValue()
Method to use for accessing binary content of binary nodes (nodes
for which
isBinary() returns true); or for Text Nodes
(ones for which getTextValue() returns non-null value),
to read decoded base64 data. |
boolean |
getBooleanValue()
Method to use for accessing JSON boolean values (value
literals 'true' and 'false').
|
BigDecimal |
getDecimalValue() |
double |
getDoubleValue() |
Iterator<JsonNode> |
getElements()
Method for accessing all value nodes of this Node, iff
this node is a JSON Array or Object node.
|
Iterator<String> |
getFieldNames()
Method for accessing names of all fields for this Node, iff
this node is a JSON Object node.
|
Iterator<Map.Entry<String,JsonNode>> |
getFields() |
int |
getIntValue()
Returns integer value for this node, if and only if
this node is numeric (
isNumber() returns true). |
long |
getLongValue() |
abstract JsonParser.NumberType |
getNumberType()
If this node is a numeric type (as per
isNumber() ),
returns native type that node uses to store the numeric
value. |
Number |
getNumberValue()
Returns numeric value for this node, if and only if
this node is numeric (
isNumber() returns true); otherwise
returns null |
JsonNode |
getPath(int index)
Deprecated.
Use
path(int) instead |
JsonNode |
getPath(String fieldName)
Deprecated.
Use
path(String) instead |
String |
getTextValue()
Method to use for accessing String values.
|
boolean |
getValueAsBoolean()
Deprecated.
Since 1.9, use
asBoolean() instead |
boolean |
getValueAsBoolean(boolean defaultValue)
Deprecated.
Since 1.9, use
asBoolean() instead |
double |
getValueAsDouble()
Deprecated.
Since 1.9, use
asDouble() instead |
double |
getValueAsDouble(double defaultValue)
Deprecated.
Since 1.9, use
asDouble() instead |
int |
getValueAsInt()
Deprecated.
Since 1.9, use
asInt() instead |
int |
getValueAsInt(int defaultValue)
Deprecated.
Since 1.9, use
asInt() instead |
long |
getValueAsLong()
Deprecated.
Since 1.9, use
asLong() instead |
long |
getValueAsLong(long defaultValue)
Deprecated.
Since 1.9, use
asLong() instead |
String |
getValueAsText()
Deprecated.
Since 1.9, use
asText() instead |
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 |
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()
Method that returns true for container nodes: Arrays and Objects.
|
boolean |
isDouble() |
boolean |
isFloatingPointNumber() |
boolean |
isInt() |
boolean |
isIntegralNumber() |
boolean |
isLong() |
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.
|
boolean |
isNull()
Method that can be used to check if this node was created from
Json liternal 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 |
isTextual() |
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.
|
Iterator<JsonNode> |
iterator()
Same as calling
getElements() ; implemented so that
convenience "for-each" loop can be used for looping over elements
of JSON Array constructs. |
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. |
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.
|
abstract String |
toString()
Note: marked as abstract to ensure all implementation
classes define it properly.
|
abstract JsonParser |
traverse()
Method for constructing a
JsonParser instance for
iterating over contents of the tree that this
node is root of. |
JsonNode |
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 and
return such object node.
|
public boolean isValueNode()
Note: one and only one of methods isValueNode()
,
isContainerNode()
and isMissingNode()
ever
returns true for any given node.
public boolean isContainerNode()
Note: one and only one of methods isValueNode()
,
isContainerNode()
and isMissingNode()
ever
returns true for any given node.
public boolean isMissingNode()
Note: one and only one of methods isValueNode()
,
isContainerNode()
and isMissingNode()
ever
returns true for any given node.
public boolean isArray()
public boolean isObject()
public boolean isPojo()
POJONode
.public boolean isNumber()
public boolean isIntegralNumber()
public boolean isFloatingPointNumber()
public boolean isInt()
public boolean isLong()
isInt()
returns false)public boolean isDouble()
public boolean isBigDecimal()
public boolean isBigInteger()
public boolean isTextual()
public boolean isBoolean()
public boolean isNull()
public boolean isBinary()
isTextual()
will
return false if this method returns true.public abstract JsonToken asToken()
JsonToken
that equivalent
stream event would produce (for most nodes there is just
one token but for structured/container types multiple)public abstract JsonParser.NumberType getNumberType()
isNumber()
),
returns native type that node uses to store the numeric
value.public String getTextValue()
isTextual()
returns
false) null will be returned.
For String values, null is never returned (but empty Strings may be)public byte[] getBinaryValue() throws IOException
isBinary()
returns true); or for Text Nodes
(ones for which getTextValue()
returns non-null value),
to read decoded base64 data.
For other types of nodes, returns null.IOException
public boolean getBooleanValue()
public Number getNumberValue()
isNumber()
returns true); otherwise
returns nullpublic int getIntValue()
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.public long getLongValue()
public double getDoubleValue()
public BigDecimal getDecimalValue()
public BigInteger getBigIntegerValue()
public JsonNode get(int index)
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.
public JsonNode get(String fieldName)
public abstract String asText()
isValueNode()
returns true), otherwise
empty String.getValueAsText
)public int asInt()
If representation can not be converted to an int (including structured types like Objects and Arrays), default value of 0 will be returned; no exceptions are thrown.
getValueAsInt
)public int asInt(int defaultValue)
If representation can not be converted to an int (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
getValueAsInt
)public long asLong()
If representation can not be converted to an long (including structured types like Objects and Arrays), default value of 0 will be returned; no exceptions are thrown.
getValueAsLong
)public long asLong(long defaultValue)
If representation can not be converted to an long (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
getValueAsLong
)public double asDouble()
If representation can not be converted to an int (including structured types like Objects and Arrays), default value of 0.0 will be returned; no exceptions are thrown.
getValueAsDouble
)public double asDouble(double defaultValue)
If representation can not be converted to an int (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
getValueAsLong
)public boolean asBoolean()
If representation can not be converted to a boolean value (including structured types like Objects and Arrays), default value of false will be returned; no exceptions are thrown.
getValueAsBoolean
)public boolean asBoolean(boolean defaultValue)
If representation can not be converted to a boolean value (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
getValueAsBoolean
)@Deprecated public String getValueAsText()
asText()
insteadisValueNode()
returns true), otherwise null.
Note: to serialize nodes of any type, you should call
toString()
instead.
@Deprecated public int getValueAsInt()
asInt()
insteadIf representation can not be converted to an int (including structured types like Objects and Arrays), default value of 0 will be returned; no exceptions are thrown.
@Deprecated public int getValueAsInt(int defaultValue)
asInt()
insteadIf representation can not be converted to an int (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
@Deprecated public long getValueAsLong()
asLong()
insteadIf representation can not be converted to an long (including structured types like Objects and Arrays), default value of 0 will be returned; no exceptions are thrown.
@Deprecated public long getValueAsLong(long defaultValue)
asLong()
insteadIf representation can not be converted to an long (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
@Deprecated public double getValueAsDouble()
asDouble()
insteadIf representation can not be converted to an int (including structured types like Objects and Arrays), default value of 0.0 will be returned; no exceptions are thrown.
@Deprecated public double getValueAsDouble(double defaultValue)
asDouble()
insteadIf representation can not be converted to an int (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
@Deprecated public boolean getValueAsBoolean()
asBoolean()
insteadIf representation can not be converted to a boolean value (including structured types like Objects and Arrays), default value of false will be returned; no exceptions are thrown.
@Deprecated public boolean getValueAsBoolean(boolean defaultValue)
asBoolean()
insteadIf representation can not be converted to a boolean value (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.
public boolean has(String fieldName)
This method is equivalent to:
node.get(fieldName) != null(since return value of get() is node, not value node contains)
fieldName
- Name of element to checkpublic boolean has(int index)
Note: array element indexes are 0-based.
This method is equivalent to:
node.get(index) != null
index
- Index to checkpublic abstract JsonNode findValue(String fieldName)
fieldName
- Name of field to look forpublic final List<JsonNode> findValues(String fieldName)
fieldName
- Name of field to look forpublic final List<String> findValuesAsText(String fieldName)
findValues(java.lang.String)
, but will additionally convert
values into Strings, calling getValueAsText()
.public abstract JsonNode findPath(String fieldName)
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.fieldName
- Name of field to look forpublic abstract JsonNode findParent(String fieldName)
fieldName
- Name of field to look forpublic final List<JsonNode> findParents(String fieldName)
fieldName
- Name of field to look forpublic abstract List<String> findValuesAsText(String fieldName, List<String> foundSoFar)
public int size()
public final Iterator<JsonNode> iterator()
getElements()
; implemented so that
convenience "for-each" loop can be used for looping over elements
of JSON Array constructs.public Iterator<JsonNode> getElements()
public Iterator<String> getFieldNames()
public Iterator<Map.Entry<String,JsonNode>> getFields()
public abstract JsonNode path(String fieldName)
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.@Deprecated public final JsonNode getPath(String fieldName)
path(String)
insteadpath(String)
.public abstract JsonNode path(int index)
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.@Deprecated public final JsonNode getPath(int index)
path(int)
insteadpath(int)
.public JsonNode with(String propertyName)
UnsupportedOperationException
is thrownpublic abstract JsonParser traverse()
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.public abstract String toString()
Note: marked as abstract to ensure all implementation classes define it properly.
public abstract boolean equals(Object o)
Note: marked as abstract to ensure all implementation
classes define it properly and not rely on definition
from Object
.