Package com.fasterxml.jackson.databind.node

Class TreeTraversingParser

java.lang.Object

com.fasterxml.jackson.core.JsonParser

com.fasterxml.jackson.core.base.ParserMinimalBase

com.fasterxml.jackson.databind.node.TreeTraversingParser

All Implemented Interfaces:

Versioned, Closeable, AutoCloseable

public class TreeTraversingParser
extends ParserMinimalBase

Facade over JsonNode that implements JsonParser to allow accessing contents of JSON tree in alternate form (stream of tokens). Useful when a streaming source is expected by code, such as data binding functionality.

Nested Class Summary

Nested classes/interfaces inherited from class com.fasterxml.jackson.core.JsonParser

JsonParser.Feature, JsonParser.NumberType

Constructor Summary

Constructors

Constructor	Description
TreeTraversingParser(JsonNode n)
TreeTraversingParser(JsonNode n, ObjectCodec codec)

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the parser so that no further iteration or data access can be made; will also close the underlying input source if parser either owns the input source, or feature JsonParser.Feature.AUTO_CLOSE_SOURCE is enabled.
BigInteger	getBigIntegerValue()	Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it can not be used as a Java long primitive type due to its magnitude.
byte[]	getBinaryValue(Base64Variant b64variant)	Method that can be used to read (and consume -- results may not be accessible using other methods after the call) base64-encoded binary data included in the current textual JSON value.
ObjectCodec	getCodec()	Accessor for ObjectCodec associated with this parser, if any.
JsonLocation	getCurrentLocation()	Method that returns location of the last processed character; usually for error reporting purposes.
String	getCurrentName()	Method that can be called to get the name associated with the current token: for JsonToken.FIELD_NAMEs it will be the same as what JsonParser.getText() returns; for field values it will be preceding field name; and for others (array values, root-level values) null.
BigDecimal	getDecimalValue()	Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_FLOAT or JsonToken.VALUE_NUMBER_INT.
double	getDoubleValue()	Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_FLOAT and it can be expressed as a Java double primitive type.
Object	getEmbeddedObject()	Accessor that can be called if (and only if) the current token is JsonToken.VALUE_EMBEDDED_OBJECT.
float	getFloatValue()	Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_FLOAT and it can be expressed as a Java float primitive type.
int	getIntValue()	Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it can be expressed as a value of Java int primitive type.
long	getLongValue()	Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it can be expressed as a Java long primitive type.
JsonParser.NumberType	getNumberType()	If current token is of type JsonToken.VALUE_NUMBER_INT or JsonToken.VALUE_NUMBER_FLOAT, returns one of JsonParser.NumberType constants; otherwise returns null.
Number	getNumberValue()	Generic number value accessor method that will work for all kinds of numeric values.
JsonStreamContext	getParsingContext()	Method that can be used to access current parsing context reader is in.
String	getText()	Method for accessing textual representation of the current token; if no current token (before first call to JsonParser.nextToken(), or after encountering end-of-input), returns null.
char[]	getTextCharacters()	Method similar to JsonParser.getText(), but that will return underlying (unmodifiable) character array that contains textual value, instead of constructing a String object to contain this information.
int	getTextLength()	Accessor used with JsonParser.getTextCharacters(), to know length of String stored in returned buffer.
int	getTextOffset()	Accessor used with JsonParser.getTextCharacters(), to know offset of the first text content character within buffer.
JsonLocation	getTokenLocation()	Method that return the starting location of the current token; that is, position of the first character from input that starts the current token.
boolean	hasTextCharacters()	Method that can be used to determine whether calling of JsonParser.getTextCharacters() would be the most efficient way to access textual content for the event parser currently points to.
boolean	isClosed()	Method that can be called to determine whether this parser is closed or not.
boolean	isNaN()	Access for checking whether current token is a numeric value token, but one that is of "not-a-number" (NaN) variety (including both "NaN" AND positive/negative infinity!): not supported by all formats, but often supported for JsonToken.VALUE_NUMBER_FLOAT.
JsonToken	nextToken()	Main iteration method, which will advance stream enough to determine type of the next token, if any.
void	overrideCurrentName(String name)	Method that can be used to change what is considered to be the current (field) name.
int	readBinaryValue(Base64Variant b64variant, OutputStream out)	Similar to JsonParser.readBinaryValue(OutputStream) but allows explicitly specifying base64 variant to use.
void	setCodec(ObjectCodec c)	Setter that allows defining ObjectCodec associated with this parser, if any.
JsonParser	skipChildren()	Method that will skip all child tokens of an array or object token that the parser currently points to, iff stream points to JsonToken.START_OBJECT or JsonToken.START_ARRAY.
Version	version()	Accessor for getting version of the core package, given a parser instance.

Methods inherited from class com.fasterxml.jackson.core.base.ParserMinimalBase

clearCurrentToken, currentToken, currentTokenId, getCurrentToken, getCurrentTokenId, getLastClearedToken, getValueAsBoolean, getValueAsDouble, getValueAsInt, getValueAsInt, getValueAsLong, getValueAsLong, getValueAsString, getValueAsString, hasCurrentToken, hasToken, hasTokenId, isExpectedStartArrayToken, isExpectedStartObjectToken, nextValue

Methods inherited from class com.fasterxml.jackson.core.JsonParser

canParseAsync, canReadObjectId, canReadTypeId, canUseSchema, configure, currentName, disable, enable, finishToken, getBinaryValue, getBooleanValue, getByteValue, getCurrentValue, getFeatureMask, getFormatFeatures, getInputSource, getNonBlockingInputFeeder, getObjectId, getSchema, getShortValue, getText, getTypeId, getValueAsBoolean, getValueAsDouble, isEnabled, isEnabled, nextBooleanValue, nextFieldName, nextFieldName, nextIntValue, nextLongValue, nextTextValue, overrideFormatFeatures, overrideStdFeatures, readBinaryValue, readValueAs, readValueAs, readValueAsTree, readValuesAs, readValuesAs, releaseBuffered, releaseBuffered, requiresCustomCodec, setCurrentValue, setFeatureMask, setRequestPayloadOnError, setRequestPayloadOnError, setRequestPayloadOnError, setSchema

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TreeTraversingParser

public TreeTraversingParser(JsonNode n)

TreeTraversingParser

public TreeTraversingParser(JsonNode n,
                            ObjectCodec codec)

Method Detail

setCodec

public void setCodec(ObjectCodec c)

Description copied from class: JsonParser

Setter that allows defining ObjectCodec associated with this parser, if any. Codec is used by JsonParser.readValueAs(Class) method (and its variants).

Specified by:

setCodec in class JsonParser

getCodec

public ObjectCodec getCodec()

Description copied from class: JsonParser

Accessor for ObjectCodec associated with this parser, if any. Codec is used by JsonParser.readValueAs(Class) method (and its variants).

Specified by:

getCodec in class JsonParser

version

public Version version()

Description copied from class: JsonParser

Accessor for getting version of the core package, given a parser instance. Left for sub-classes to implement.

Specified by:

version in interface Versioned

Specified by:

version in class JsonParser

close

public void close()
           throws IOException

Description copied from class: JsonParser

Closes the parser so that no further iteration or data access can be made; will also close the underlying input source if parser either owns the input source, or feature JsonParser.Feature.AUTO_CLOSE_SOURCE is enabled. Whether parser owns the input source depends on factory method that was used to construct instance (so check JsonFactory for details, but the general idea is that if caller passes in closable resource (such as InputStream or Reader) parser does NOT own the source; but if it passes a reference (such as File or URL and creates stream or reader it does own them.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in class ParserMinimalBase

Throws:

IOException

nextToken

public JsonToken nextToken()
                    throws IOException,
                           JsonParseException

Description copied from class: JsonParser

Main iteration method, which will advance stream enough to determine type of the next token, if any. If none remaining (stream has no content other than possible white space before ending), null will be returned.

Specified by:

nextToken in class ParserMinimalBase

Returns:

Next token from the stream, if any found, or null to indicate end-of-input

Throws:

IOException

JsonParseException

skipChildren

public JsonParser skipChildren()
                        throws IOException

Description copied from class: JsonParser

Method that will skip all child tokens of an array or object token that the parser currently points to, iff stream points to JsonToken.START_OBJECT or JsonToken.START_ARRAY. If not, it will do nothing. After skipping, stream will point to matching JsonToken.END_OBJECT or JsonToken.END_ARRAY (possibly skipping nested pairs of START/END OBJECT/ARRAY tokens as well as value tokens). The idea is that after calling this method, application will call JsonParser.nextToken() to point to the next available token, if any.

Overrides:

skipChildren in class ParserMinimalBase

Throws:

IOException

isClosed

public boolean isClosed()

Description copied from class: JsonParser

Method that can be called to determine whether this parser is closed or not. If it is closed, no new tokens can be retrieved by calling JsonParser.nextToken() (and the underlying stream may be closed). Closing may be due to an explicit call to JsonParser.close() or because parser has encountered end of input.

Specified by:

isClosed in class ParserMinimalBase

getCurrentName

public String getCurrentName()

Description copied from class: JsonParser

Method that can be called to get the name associated with the current token: for JsonToken.FIELD_NAMEs it will be the same as what JsonParser.getText() returns; for field values it will be preceding field name; and for others (array values, root-level values) null.

Specified by:

getCurrentName in class ParserMinimalBase

overrideCurrentName

public void overrideCurrentName(String name)

Description copied from class: JsonParser

Method that can be used to change what is considered to be the current (field) name. May be needed to support non-JSON data formats or unusual binding conventions; not needed for typical processing.

Note that use of this method should only be done as sort of last resort, as it is a work-around for regular operation.

Specified by:

overrideCurrentName in class ParserMinimalBase

Parameters:

name - Name to use as the current name; may be null.

getParsingContext

public JsonStreamContext getParsingContext()

Description copied from class: JsonParser

Method that can be used to access current parsing context reader is in. There are 3 different types: root, array and object contexts, with slightly different available information. Contexts are hierarchically nested, and can be used for example for figuring out part of the input document that correspond to specific array or object (for highlighting purposes, or error reporting). Contexts can also be used for simple xpath-like matching of input, if so desired.

Specified by:

getParsingContext in class ParserMinimalBase

getTokenLocation

public JsonLocation getTokenLocation()

Description copied from class: JsonParser

Method that return the starting location of the current token; that is, position of the first character from input that starts the current token.

Specified by:

getTokenLocation in class JsonParser

getCurrentLocation

public JsonLocation getCurrentLocation()

Description copied from class: JsonParser

Method that returns location of the last processed character; usually for error reporting purposes.

Specified by:

getCurrentLocation in class JsonParser

getText

public String getText()

Description copied from class: JsonParser

Method for accessing textual representation of the current token; if no current token (before first call to JsonParser.nextToken(), or after encountering end-of-input), returns null. Method can be called for any token type.

Specified by:

getText in class ParserMinimalBase

getTextCharacters

public char[] getTextCharacters()
                         throws IOException,
                                JsonParseException

Description copied from class: JsonParser

Method similar to JsonParser.getText(), but that will return underlying (unmodifiable) character array that contains textual value, instead of constructing a String object to contain this information. Note, however, that:

• Textual contents are not guaranteed to start at index 0 (rather, call JsonParser.getTextOffset()) to know the actual offset
• Length of textual contents may be less than the length of returned buffer: call JsonParser.getTextLength() for actual length of returned content.

Note that caller MUST NOT modify the returned character array in any way -- doing so may corrupt current parser state and render parser instance useless.

The only reason to call this method (over JsonParser.getText()) is to avoid construction of a String object (which will make a copy of contents).

Specified by:

getTextCharacters in class ParserMinimalBase

Throws:

IOException

JsonParseException

getTextLength

public int getTextLength()
                  throws IOException,
                         JsonParseException

Description copied from class: JsonParser

Accessor used with JsonParser.getTextCharacters(), to know length of String stored in returned buffer.

Specified by:

getTextLength in class ParserMinimalBase

Returns:

Number of characters within buffer returned by JsonParser.getTextCharacters() that are part of textual content of the current token.

Throws:

IOException

JsonParseException

getTextOffset

public int getTextOffset()
                  throws IOException,
                         JsonParseException

Description copied from class: JsonParser

Accessor used with JsonParser.getTextCharacters(), to know offset of the first text content character within buffer.

Specified by:

getTextOffset in class ParserMinimalBase

Returns:

Offset of the first character within buffer returned by JsonParser.getTextCharacters() that is part of textual content of the current token.

Throws:

IOException

JsonParseException

hasTextCharacters

public boolean hasTextCharacters()

Description copied from class: JsonParser

Method that can be used to determine whether calling of JsonParser.getTextCharacters() would be the most efficient way to access textual content for the event parser currently points to.

Default implementation simply returns false since only actual implementation class has knowledge of its internal buffering state. Implementations are strongly encouraged to properly override this method, to allow efficient copying of content by other code.

Specified by:

hasTextCharacters in class ParserMinimalBase

Returns:

True if parser currently has character array that can be efficiently returned via JsonParser.getTextCharacters(); false means that it may or may not exist

getNumberType

public JsonParser.NumberType getNumberType()
                                    throws IOException

Description copied from class: JsonParser

If current token is of type JsonToken.VALUE_NUMBER_INT or JsonToken.VALUE_NUMBER_FLOAT, returns one of JsonParser.NumberType constants; otherwise returns null.

Specified by:

getNumberType in class JsonParser

Throws:

IOException

getBigIntegerValue

public BigInteger getBigIntegerValue()
                              throws IOException

Description copied from class: JsonParser

Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it can not be used as a Java long primitive type due to its magnitude. It can also be called for JsonToken.VALUE_NUMBER_FLOAT; if so, it is equivalent to calling JsonParser.getDecimalValue() and then constructing a BigInteger from that value.

Specified by:

getBigIntegerValue in class JsonParser

Throws:

IOException

getDecimalValue

public BigDecimal getDecimalValue()
                           throws IOException

Description copied from class: JsonParser

Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_FLOAT or JsonToken.VALUE_NUMBER_INT. No under/overflow exceptions are ever thrown.

Specified by:

getDecimalValue in class JsonParser

Throws:

IOException

getDoubleValue

public double getDoubleValue()
                      throws IOException

Description copied from class: JsonParser

Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_FLOAT and it can be expressed as a Java double primitive type. It can also be called for JsonToken.VALUE_NUMBER_INT; if so, it is equivalent to calling JsonParser.getLongValue() and then casting; except for possible overflow/underflow exception.

Note: if the value falls outside of range of Java double, a JsonParseException will be thrown to indicate numeric overflow/underflow.

Specified by:

getDoubleValue in class JsonParser

Throws:

IOException

getFloatValue

public float getFloatValue()
                    throws IOException

Description copied from class: JsonParser

Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_FLOAT and it can be expressed as a Java float primitive type. It can also be called for JsonToken.VALUE_NUMBER_INT; if so, it is equivalent to calling JsonParser.getLongValue() and then casting; except for possible overflow/underflow exception.

Note: if the value falls outside of range of Java float, a JsonParseException will be thrown to indicate numeric overflow/underflow.

Specified by:

getFloatValue in class JsonParser

Throws:

IOException

getIntValue

public int getIntValue()
                throws IOException

Description copied from class: JsonParser

Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it can be expressed as a value of Java int primitive type. It can also be called for JsonToken.VALUE_NUMBER_FLOAT; if so, it is equivalent to calling JsonParser.getDoubleValue() and then casting; except for possible overflow/underflow exception.

Note: if the resulting integer value falls outside range of Java int, a JsonParseException may be thrown to indicate numeric overflow/underflow.

Specified by:

getIntValue in class JsonParser

Throws:

IOException

getLongValue

public long getLongValue()
                  throws IOException

Description copied from class: JsonParser

Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it can be expressed as a Java long primitive type. It can also be called for JsonToken.VALUE_NUMBER_FLOAT; if so, it is equivalent to calling JsonParser.getDoubleValue() and then casting to int; except for possible overflow/underflow exception.

Note: if the token is an integer, but its value falls outside of range of Java long, a JsonParseException may be thrown to indicate numeric overflow/underflow.

Specified by:

getLongValue in class JsonParser

Throws:

IOException

getNumberValue

public Number getNumberValue()
                      throws IOException

Description copied from class: JsonParser

Generic number value accessor method that will work for all kinds of numeric values. It will return the optimal (simplest/smallest possible) wrapper object that can express the numeric value just parsed.

Specified by:

getNumberValue in class JsonParser

Throws:

IOException

getEmbeddedObject

public Object getEmbeddedObject()

Description copied from class: JsonParser

Accessor that can be called if (and only if) the current token is JsonToken.VALUE_EMBEDDED_OBJECT. For other token types, null is returned.

Note: only some specialized parser implementations support embedding of objects (usually ones that are facades on top of non-streaming sources, such as object trees). One exception is access to binary content (whether via base64 encoding or not) which typically is accessible using this method, as well as JsonParser.getBinaryValue().

Overrides:

getEmbeddedObject in class JsonParser

isNaN

public boolean isNaN()

Description copied from class: JsonParser

Access for checking whether current token is a numeric value token, but one that is of "not-a-number" (NaN) variety (including both "NaN" AND positive/negative infinity!): not supported by all formats, but often supported for JsonToken.VALUE_NUMBER_FLOAT. NOTE: roughly equivalent to calling !Double.isFinite() on value you would get from calling JsonParser.getDoubleValue().

Overrides:

isNaN in class JsonParser

getBinaryValue

public byte[] getBinaryValue(Base64Variant b64variant)
                      throws IOException,
                             JsonParseException

Description copied from class: JsonParser

Method that can be used to read (and consume -- results may not be accessible using other methods after the call) base64-encoded binary data included in the current textual JSON value. It works similar to getting String value via JsonParser.getText() and decoding result (except for decoding part), but should be significantly more performant.

Note that non-decoded textual contents of the current token are not guaranteed to be accessible after this method is called. Current implementation, for example, clears up textual content during decoding. Decoded binary content, however, will be retained until parser is advanced to the next event.

Specified by:

getBinaryValue in class ParserMinimalBase

Parameters:

b64variant - Expected variant of base64 encoded content (see Base64Variants for definitions of "standard" variants).

Returns:

Decoded binary data

Throws:

IOException

JsonParseException

readBinaryValue

public int readBinaryValue(Base64Variant b64variant,
                           OutputStream out)
                    throws IOException,
                           JsonParseException

Description copied from class: JsonParser

Similar to JsonParser.readBinaryValue(OutputStream) but allows explicitly specifying base64 variant to use.

Overrides:

readBinaryValue in class JsonParser

Parameters:

b64variant - base64 variant to use

out - Output stream to use for passing decoded binary data

Returns:

Number of bytes that were decoded and written via OutputStream

Throws:

IOException

JsonParseException