Class JsonGenerator
- All Implemented Interfaces:
Versioned
,Closeable
,Flushable
,AutoCloseable
- Direct Known Subclasses:
GeneratorBase
,JsonGeneratorDelegate
JsonFactory
instance.- Author:
- Tatu Saloranta
-
Nested Class Summary
Modifier and TypeClassDescriptionstatic enum
Enumeration that defines all togglable features for generators. -
Field Summary
Modifier and TypeFieldDescriptionprotected PrettyPrinter
Object that handles pretty-printing (usually additional white space to make results more human-readable) during output.protected static final JacksonFeatureSet<StreamWriteCapability>
Default set ofStreamWriteCapability
ies for typical binary formats, to use either as-is, or as a base with possible differences.protected static final JacksonFeatureSet<StreamWriteCapability>
Default set ofStreamWriteCapability
ies for typical textual formats, to use either as-is, or as a base with possible differences.protected static final JacksonFeatureSet<StreamWriteCapability>
Default set ofStreamWriteCapability
ies that may be used as basis for format-specific readers (or as bogus instance if non-null set needs to be passed). -
Constructor Summary
-
Method Summary
Modifier and TypeMethodDescriptionprotected void
protected void
Method for copying currentJsonToken.VALUE_NUMBER_FLOAT
value; overridable by format backend implementations.protected void
Method for copying currentJsonToken.VALUE_NUMBER_FLOAT
value; overridable by format backend implementations.protected void
Method for copying currentJsonToken.VALUE_NUMBER_FLOAT
value; overridable by format backend implementations.protected void
Method for copying currentJsonToken.VALUE_STRING
value; overridable by format backend implementations.protected void
_reportError
(String msg) Helper method used for constructing and throwingJsonGenerationException
with given base message.protected void
protected final void
protected final void
_verifyOffsets
(int arrayLength, int offset, int length) protected void
_writeSimpleObject
(Object value) Helper method to try to call appropriate write method for given untyped Object.void
Helper method, usually equivalent to:getOutputContext().setCurrentValue(v);
boolean
Introspection method to call to check whether it is ok to omit writing of Object fields or not.boolean
canUseSchema
(FormatSchema schema) Method that can be used to verify that given schema can be used with this generator (usingsetSchema(com.fasterxml.jackson.core.FormatSchema)
).boolean
Introspection method that may be called to see if the underlying data format supports "native" binary data; that is, an efficient output of binary content without encoding.boolean
Introspection method to call to check whether it is possible to write numbers usingwriteNumber(java.lang.String)
using possible custom format, or not.boolean
Introspection method that may be called to see if the underlying data format supports some kind of Object Ids natively (many do not; for example, JSON doesn't).boolean
Introspection method that may be called to see if the underlying data format supports some kind of Type Ids natively (many do not; for example, JSON doesn't).abstract void
close()
Method called to close this generator, so that no more content can be written.final JsonGenerator
configure
(JsonGenerator.Feature f, boolean state) Method for enabling or disabling specified feature: checkJsonGenerator.Feature
for list of available features.void
Method for copying contents of the current event that the given parser instance points to.void
Same ascopyCurrentEvent(com.fasterxml.jackson.core.JsonParser)
with the exception that copying of numeric values tries to avoid any conversion losses; in particular for floating-point numbers.void
Method for copying contents of the current event and following events that it encloses the given parser instance points to.Helper method, usually equivalent to:getOutputContext().getCurrentValue();
abstract JsonGenerator
Method for disabling specified feature (checkJsonGenerator.Feature
for list of features)abstract JsonGenerator
Method for enabling specified generator feature: checkJsonGenerator.Feature
for list of available features.abstract void
flush()
Method called to flush any buffered content to the underlying target (output stream, writer), and to flush the target itself as well.Method for accessing custom escapes factory uses forJsonGenerator
s it creates.abstract ObjectCodec
getCodec()
Method for accessing the object used for writing Java object as JSON content (using methodwriteObject(java.lang.Object)
).Alias forcurrentValue()
, to be deprecated in later Jackson 2.x versions (and removed from Jackson 3.0).abstract int
Bulk access method for getting state of all standard (non-dataformat-specific)JsonGenerator.Feature
s.int
Bulk access method for getting state of allFormatFeature
s, format-specific on/off configuration settings.int
Accessor method for testing what is the highest unescaped character configured for this generator.int
Method for verifying amount of content that is buffered by generator but not yet flushed to the underlying target (stream, writer), in units (byte, char) that the generator implementation uses for buffering; or -1 if this information is not available.abstract JsonStreamContext
Accessor for context object that provides information about low-level logical position withing output token stream.Method that can be used to get access to object that is used as target for generated output; this is usually eitherOutputStream
orWriter
, depending on what generator was constructed with.Accessor for checking whether this generator has a configuredPrettyPrinter
; returns it if so, null if none configured.Method for accessing Schema that this generator uses, if any;null
if none.Accessor for getting metadata on capabilities of this generator, based on underlying data format being read (directly or indirectly).abstract boolean
isClosed()
Method that can be called to determine whether this generator is closed or not.abstract boolean
Method for checking whether given feature is enabled.boolean
Method for checking whether given feature is enabled.overrideFormatFeatures
(int values, int mask) Bulk set method for (re)setting states ofFormatFeature
s, by specifying values (set / clear) along with a mask, to determine which features to change, if any.overrideStdFeatures
(int values, int mask) Bulk set method for (re)setting states of features specified bymask
.Method for defining custom escapes factory uses forJsonGenerator
s it creates.abstract JsonGenerator
setCodec
(ObjectCodec oc) Method that can be called to set or reset the object to use for writing Java objects as JsonContent (using methodwriteObject(java.lang.Object)
).void
Alias forassignCurrentValue(java.lang.Object)
, to be deprecated in later Jackson 2.x versions (and removed from Jackson 3.0).abstract JsonGenerator
setFeatureMask
(int values) Deprecated.setHighestNonEscapedChar
(int charCode) Method that can be called to request that generator escapes all character codes above specified code point (if positive value); or, to not escape any characters except for ones that must be escaped for the data format (if -1).Method for setting a custom pretty printer, which is usually used to add indentation for improved human readability.Method that allows overriding String used for separating root-level JSON values (default is single space character)void
setSchema
(FormatSchema schema) Method to call to make this generator use specified schema.Get the constraints to apply when performing streaming writes.abstract JsonGenerator
Convenience method for enabling pretty-printing using the default pretty printer (DefaultPrettyPrinter
).abstract Version
version()
Accessor for finding out version of the bundle that provided this generator instance.void
writeArray
(double[] array, int offset, int length) Value write method that can be called to write a single array (sequence ofJsonToken.START_ARRAY
, zero or moreJsonToken.VALUE_NUMBER_FLOAT
,JsonToken.END_ARRAY
)void
writeArray
(int[] array, int offset, int length) Value write method that can be called to write a single array (sequence ofJsonToken.START_ARRAY
, zero or moreJsonToken.VALUE_NUMBER_INT
,JsonToken.END_ARRAY
)void
writeArray
(long[] array, int offset, int length) Value write method that can be called to write a single array (sequence ofJsonToken.START_ARRAY
, zero or moreJsonToken.VALUE_NUMBER_INT
,JsonToken.END_ARRAY
)void
writeArray
(String[] array, int offset, int length) Value write method that can be called to write a single array (sequence ofJsonToken.START_ARRAY
, zero or moreJsonToken.VALUE_STRING
,JsonToken.END_ARRAY
)void
writeArrayFieldStart
(String fieldName) Convenience method for outputting a field entry ("member") (that will contain a JSON Array value), and the START_ARRAY marker.void
writeBinary
(byte[] data) Similar towriteBinary(Base64Variant,byte[],int,int)
, but assumes default to using the Jackson default Base64 variant (which isBase64Variants.MIME_NO_LINEFEEDS
).void
writeBinary
(byte[] data, int offset, int len) Similar towriteBinary(Base64Variant,byte[],int,int)
, but default to using the Jackson default Base64 variant (which isBase64Variants.MIME_NO_LINEFEEDS
).abstract void
writeBinary
(Base64Variant bv, byte[] data, int offset, int len) Method that will output given chunk of binary data as base64 encoded, as a complete String value (surrounded by double quotes).abstract int
writeBinary
(Base64Variant bv, InputStream data, int dataLength) Method similar towriteBinary(Base64Variant,byte[],int,int)
, but where input is provided through a stream, allowing for incremental writes without holding the whole input in memory.int
writeBinary
(InputStream data, int dataLength) Similar towriteBinary(Base64Variant,InputStream,int)
, but assumes default to using the Jackson default Base64 variant (which isBase64Variants.MIME_NO_LINEFEEDS
).void
writeBinaryField
(String fieldName, byte[] data) Convenience method for outputting a field entry ("member") that contains specified data in base64-encoded form.abstract void
writeBoolean
(boolean state) Method for outputting literal JSON boolean value (one of Strings 'true' and 'false').void
writeBooleanField
(String fieldName, boolean value) Convenience method for outputting a field entry ("member") that has a boolean value.void
writeEmbeddedObject
(Object object) Method that can be called on backends that support passing opaque native values that some data formats support; not used with JSON backend, more common with binary formats.abstract void
Method for writing closing marker of a JSON Array value (character ']'; plus possible white space decoration if pretty-printing is enabled).abstract void
Method for writing closing marker of an Object value (character '}'; plus possible white space decoration if pretty-printing is enabled).void
writeFieldId
(long id) Alternative towriteFieldName(String)
that may be used in cases where property key is of numeric type; either where underlying format supports such notion (some binary formats do, unlike JSON), or for convenient conversion into String presentation.abstract void
Method similar towriteFieldName(String)
, main difference being that it may perform better as some of processing (such as quoting of certain characters, or encoding into external encoding if supported by generator) can be done just once and reused for later calls.abstract void
writeFieldName
(String name) Method for writing a field name (JSON String surrounded by double quotes: syntactically identical to a JSON String value), possibly decorated by white space if pretty-printing is enabled.abstract void
Method for outputting literal JSON null value.void
writeNullField
(String fieldName) Convenience method for outputting a field entry ("member") that has JSON literal value null.void
writeNumber
(char[] encodedValueBuffer, int offset, int len) Overloaded version ofwriteNumber(String)
with same semantics but possibly more efficient operation.abstract void
writeNumber
(double v) Method for outputting indicate JSON numeric value.abstract void
writeNumber
(float v) Method for outputting indicate JSON numeric value.abstract void
writeNumber
(int v) Method for outputting given value as JSON number.abstract void
writeNumber
(long v) Method for outputting given value as JSON number.void
writeNumber
(short v) Method for outputting given value as JSON number.abstract void
writeNumber
(String encodedValue) Write method that can be used for custom numeric types that can not be (easily?) converted to "standard" Java number types.abstract void
Method for outputting indicate JSON numeric value.abstract void
Method for outputting given value as JSON number.void
writeNumberField
(String fieldName, double value) Convenience method for outputting a field entry ("member") that has the specified numeric value.void
writeNumberField
(String fieldName, float value) Convenience method for outputting a field entry ("member") that has the specified numeric value.void
writeNumberField
(String fieldName, int value) Convenience method for outputting a field entry ("member") that has the specified numeric value.void
writeNumberField
(String fieldName, long value) Convenience method for outputting a field entry ("member") that has the specified numeric value.void
writeNumberField
(String fieldName, short value) Convenience method for outputting a field entry ("member") that has the specified numeric value.void
writeNumberField
(String fieldName, BigDecimal value) Convenience method for outputting a field entry ("member") that has the specified numeric value.void
writeNumberField
(String fieldName, BigInteger value) Convenience method for outputting a field entry ("member") that has the specified numeric value.abstract void
writeObject
(Object pojo) Older alias forwritePOJO(Object)
void
writeObjectField
(String fieldName, Object pojo) Older alias forwritePOJOField(java.lang.String, java.lang.Object)
void
writeObjectFieldStart
(String fieldName) Convenience method for outputting a field entry ("member") (that will contain an Object value), and the START_OBJECT marker.void
writeObjectId
(Object id) Method that can be called to output so-called native Object Id.void
writeObjectRef
(Object referenced) Method that can be called to output references to native Object Ids.void
writeOmittedField
(String fieldName) Method called to indicate that a property in this position was skipped.void
Method for writing given Java object (POJO) as JSON.void
writePOJOField
(String fieldName, Object pojo) Convenience method for outputting a field entry ("member") that has contents of specific Java object as its value.abstract void
writeRaw
(char c) Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such).abstract void
writeRaw
(char[] text, int offset, int len) Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such).void
Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such).abstract void
Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such).abstract void
Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such).abstract void
writeRawUTF8String
(byte[] buffer, int offset, int len) Method similar towriteString(String)
but that takes as its input a UTF-8 encoded String that is to be output as-is, without additional escaping (type of which depends on data format; backslashes for JSON).abstract void
writeRawValue
(char[] text, int offset, int len) void
Method similar towriteRawValue(String)
, but potentially more efficient as it may be able to use pre-encoded content (similar towriteRaw(SerializableString)
.abstract void
writeRawValue
(String text) Method that will force generator to copy input text verbatim without any modifications, but assuming it must constitute a single legal JSON value (number, string, boolean, null, Array or List).abstract void
writeRawValue
(String text, int offset, int len) abstract void
Method for writing starting marker of a Array value (for JSON this is character '['; plus possible white space decoration if pretty-printing is enabled).void
writeStartArray
(int size) Deprecated.Since 2.12 UsewriteStartArray(Object, int)
insteadvoid
writeStartArray
(Object forValue) Method for writing start marker of an Array value, similar towriteStartArray()
, but also specifying the "current value" to assign to the new Array context being created.void
writeStartArray
(Object forValue, int size) Method for writing start marker of an Array value, similar towriteStartArray()
, but also specifying the "current value" to assign to the new Array context being created as well as how many elements will be written for the array before callingwriteEndArray()
.abstract void
Method for writing starting marker of an Object value (character '{'; plus possible white space decoration if pretty-printing is enabled).void
writeStartObject
(Object forValue) Method for writing starting marker of an Object value to represent the given Java Object value.void
writeStartObject
(Object forValue, int size) Method for writing starting marker of an Object value to represent the given Java Object value.abstract void
writeString
(char[] buffer, int offset, int len) Method for outputting a String value.abstract void
Method similar towriteString(String)
, but that takesSerializableString
which can make this potentially more efficient to call as generator may be able to reuse quoted and/or encoded representation.void
writeString
(Reader reader, int len) Method for outputting a String value.abstract void
writeString
(String text) Method for outputting a String value.void
writeStringField
(String fieldName, String value) Convenience method for outputting a field entry ("member") that has a String value.abstract void
Method for writing given JSON tree (expressed as a tree where given JsonNode is the root) using this generator.void
writeTypeId
(Object id) Method that can be called to output so-called native Type Id.writeTypePrefix
(WritableTypeId typeIdDef) Replacement method forwriteTypeId(Object)
which is called regardless of whether format has native type ids.writeTypeSuffix
(WritableTypeId typeIdDef) Method to call along withwriteTypePrefix(com.fasterxml.jackson.core.type.WritableTypeId)
, but after actual value that has type id has been completely written.abstract void
writeUTF8String
(byte[] buffer, int offset, int len) Method similar towriteString(String)
but that takes as its input a UTF-8 encoded String which has not been escaped using whatever escaping scheme data format requires (for JSON that is backslash-escaping for control characters and double-quotes; for other formats something else).
-
Field Details
-
DEFAULT_WRITE_CAPABILITIES
Default set ofStreamWriteCapability
ies that may be used as basis for format-specific readers (or as bogus instance if non-null set needs to be passed).- Since:
- 2.12
-
DEFAULT_TEXTUAL_WRITE_CAPABILITIES
Default set ofStreamWriteCapability
ies for typical textual formats, to use either as-is, or as a base with possible differences.- Since:
- 2.12
-
DEFAULT_BINARY_WRITE_CAPABILITIES
Default set ofStreamWriteCapability
ies for typical binary formats, to use either as-is, or as a base with possible differences.- Since:
- 2.12
-
_cfgPrettyPrinter
Object that handles pretty-printing (usually additional white space to make results more human-readable) during output. If null, no pretty-printing is done.
-
-
Constructor Details
-
JsonGenerator
protected JsonGenerator()
-
-
Method Details
-
setCodec
Method that can be called to set or reset the object to use for writing Java objects as JsonContent (using methodwriteObject(java.lang.Object)
).- Parameters:
oc
- Codec to assign, if any;null
if none- Returns:
- This generator, to allow call chaining
-
getCodec
Method for accessing the object used for writing Java object as JSON content (using methodwriteObject(java.lang.Object)
).- Returns:
- Codec assigned to this generator, if any;
null
if none
-
streamWriteConstraints
Get the constraints to apply when performing streaming writes.- Since:
- 2.16
-
version
Accessor for finding out version of the bundle that provided this generator instance. -
getOutputContext
Accessor for context object that provides information about low-level logical position withing output token stream.- Returns:
- Stream output context (
JsonStreamContext
) associated with this generator
-
getOutputTarget
Method that can be used to get access to object that is used as target for generated output; this is usually eitherOutputStream
orWriter
, depending on what generator was constructed with. Note that returned value may be null in some cases; including case where implementation does not want to exposed raw source to caller. In cases where output has been decorated, object returned here is the decorated version; this allows some level of interaction between users of generator and decorator object.In general use of this accessor should be considered as "last effort", i.e. only used if no other mechanism is applicable.
- Returns:
- Output target this generator was configured with
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currentValue
Helper method, usually equivalent to:getOutputContext().getCurrentValue();
Note that "current value" is NOT populated (or used) by Streaming parser or generators; it is only used by higher-level data-binding functionality. The reason it is included here is that it can be stored and accessed hierarchically, and gets passed through data-binding.
- Returns:
- "Current value" associated with the current context (state) of this generator
- Since:
- 2.13 (added as replacement for older
getCurrentValue()
-
assignCurrentValue
Helper method, usually equivalent to:getOutputContext().setCurrentValue(v);
- Parameters:
v
- Current value to assign for the current context of this generator- Since:
- 2.13 (added as replacement for older
setCurrentValue(java.lang.Object)
-
getCurrentValue
Alias forcurrentValue()
, to be deprecated in later Jackson 2.x versions (and removed from Jackson 3.0).- Returns:
- Location of the last processed input unit (byte or character)
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setCurrentValue
Alias forassignCurrentValue(java.lang.Object)
, to be deprecated in later Jackson 2.x versions (and removed from Jackson 3.0).- Parameters:
v
- Current value to assign for the current context of this generator
-
enable
Method for enabling specified generator feature: checkJsonGenerator.Feature
for list of available features.- Parameters:
f
- Feature to enable- Returns:
- This generator, to allow call chaining
-
disable
Method for disabling specified feature (checkJsonGenerator.Feature
for list of features)- Parameters:
f
- Feature to disable- Returns:
- This generator, to allow call chaining
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configure
Method for enabling or disabling specified feature: checkJsonGenerator.Feature
for list of available features.- Parameters:
f
- Feature to enable or disablestate
- Whether to enable (true
) or disable (false
) feature- Returns:
- This generator, to allow call chaining
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isEnabled
Method for checking whether given feature is enabled. CheckJsonGenerator.Feature
for list of available features.- Parameters:
f
- Feature to check- Returns:
- True if specified feature is enabled; false if not
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isEnabled
Method for checking whether given feature is enabled. CheckJsonGenerator.Feature
for list of available features.- Parameters:
f
- Feature to check- Returns:
- True if specified feature is enabled; false if not
- Since:
- 2.10
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getFeatureMask
public abstract int getFeatureMask()Bulk access method for getting state of all standard (non-dataformat-specific)JsonGenerator.Feature
s.- Returns:
- Bit mask that defines current states of all standard
JsonGenerator.Feature
s. - Since:
- 2.3
-
setFeatureMask
Deprecated.Since 2.7, useoverrideStdFeatures(int, int)
instead -- remove from 2.9Bulk set method for (re)setting states of all standardJsonGenerator.Feature
s- Parameters:
values
- Bitmask that defines whichJsonGenerator.Feature
s are enabled and which disabled- Returns:
- This generator, to allow call chaining
- Since:
- 2.3
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overrideStdFeatures
Bulk set method for (re)setting states of features specified bymask
. Functionally equivalent toint oldState = getFeatureMask(); int newState = (oldState & ~mask) | (values & mask); setFeatureMask(newState);
but preferred as this lets caller more efficiently specify actual changes made.- Parameters:
values
- Bit mask of set/clear state for features to changemask
- Bit mask of features to change- Returns:
- This generator, to allow call chaining
- Since:
- 2.6
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getFormatFeatures
public int getFormatFeatures()Bulk access method for getting state of allFormatFeature
s, format-specific on/off configuration settings.- Returns:
- Bit mask that defines current states of all standard
FormatFeature
s. - Since:
- 2.6
-
overrideFormatFeatures
Bulk set method for (re)setting states ofFormatFeature
s, by specifying values (set / clear) along with a mask, to determine which features to change, if any.Default implementation will simply throw an exception to indicate that the generator implementation does not support any
FormatFeature
s.- Parameters:
values
- Bit mask of set/clear state for features to changemask
- Bit mask of features to change- Returns:
- This generator, to allow call chaining
- Since:
- 2.6
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setSchema
Method to call to make this generator use specified schema. Method must be called before generating any content, right after instance has been created. Note that not all generators support schemas; and those that do usually only accept specific types of schemas: ones defined for data format this generator produces.If generator does not support specified schema,
UnsupportedOperationException
is thrown.- Parameters:
schema
- Schema to use- Throws:
UnsupportedOperationException
- if generator does not support schema
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getSchema
Method for accessing Schema that this generator uses, if any;null
if none. Default implementation returns null.- Returns:
- Schema in use by this generator, if any;
null
if none
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setPrettyPrinter
Method for setting a custom pretty printer, which is usually used to add indentation for improved human readability. By default, generator does not do pretty printing.To use the default pretty printer that comes with core Jackson distribution, call
useDefaultPrettyPrinter()
instead.- Parameters:
pp
-PrettyPrinter
to assign, if any;null
if none- Returns:
- This generator, to allow call chaining
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getPrettyPrinter
Accessor for checking whether this generator has a configuredPrettyPrinter
; returns it if so, null if none configured.- Returns:
PrettyPrinter
configured for this generator, if any;null
if none
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useDefaultPrettyPrinter
Convenience method for enabling pretty-printing using the default pretty printer (DefaultPrettyPrinter
).- Returns:
- This generator, to allow call chaining
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setHighestNonEscapedChar
Method that can be called to request that generator escapes all character codes above specified code point (if positive value); or, to not escape any characters except for ones that must be escaped for the data format (if -1). To force escaping of all non-ASCII characters, for example, this method would be called with value of 127.Note that generators are NOT required to support setting of value higher than 127, because there are other ways to affect quoting (or lack thereof) of character codes between 0 and 127. Not all generators support concept of escaping, either; if so, calling this method will have no effect.
Default implementation does nothing; sub-classes need to redefine it according to rules of supported data format.
- Parameters:
charCode
- Either -1 to indicate that no additional escaping is to be done; or highest code point not to escape (meaning higher ones will be), if positive value.- Returns:
- This generator, to allow call chaining
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getHighestEscapedChar
public int getHighestEscapedChar()Accessor method for testing what is the highest unescaped character configured for this generator. This may be either positive value (when escaping configuration has been set and is in effect), or 0 to indicate that no additional escaping is in effect. Some generators may not support additional escaping: for example, generators for binary formats that do not use escaping should simply return 0.- Returns:
- Currently active limitation for highest non-escaped character, if defined; or 0 to indicate no additional escaping is performed.
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getCharacterEscapes
Method for accessing custom escapes factory uses forJsonGenerator
s it creates.- Returns:
CharacterEscapes
configured for this generator, if any;null
if none
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setCharacterEscapes
Method for defining custom escapes factory uses forJsonGenerator
s it creates.Default implementation does nothing and simply returns this instance.
- Parameters:
esc
-CharacterEscapes
to configure this generator to use, if any;null
if none- Returns:
- This generator, to allow call chaining
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setRootValueSeparator
Method that allows overriding String used for separating root-level JSON values (default is single space character)Default implementation throws
UnsupportedOperationException
.- Parameters:
sep
- Separator to use, if any; null means that no separator is automatically added- Returns:
- This generator, to allow call chaining
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getOutputBuffered
public int getOutputBuffered()Method for verifying amount of content that is buffered by generator but not yet flushed to the underlying target (stream, writer), in units (byte, char) that the generator implementation uses for buffering; or -1 if this information is not available. Unit used is often the same as the unit of underlying target (that is, `byte` forOutputStream
, `char` forWriter
), but may differ if buffering is done before encoding. Default JSON-backed implementations do use matching units.Note: non-JSON implementations will be retrofitted for 2.6 and beyond; please report if you see -1 (missing override)
- Returns:
- Amount of content buffered in internal units, if amount known and accessible; -1 if not accessible.
- Since:
- 2.6
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canUseSchema
Method that can be used to verify that given schema can be used with this generator (usingsetSchema(com.fasterxml.jackson.core.FormatSchema)
).- Parameters:
schema
- Schema to check- Returns:
- True if this generator can use given schema; false if not
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canWriteObjectId
public boolean canWriteObjectId()Introspection method that may be called to see if the underlying data format supports some kind of Object Ids natively (many do not; for example, JSON doesn't). This method must be called prior to callingwriteObjectId(java.lang.Object)
orwriteObjectRef(java.lang.Object)
.Default implementation returns false; overridden by data formats that do support native Object Ids. Caller is expected to either use a non-native notation (explicit property or such), or fail, in case it can not use native object ids.
- Returns:
True
if this generator is capable of writing "native" Object Ids (which is typically determined by capabilities of the underlying format),false
if not- Since:
- 2.3
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canWriteTypeId
public boolean canWriteTypeId()Introspection method that may be called to see if the underlying data format supports some kind of Type Ids natively (many do not; for example, JSON doesn't). This method must be called prior to callingwriteTypeId(java.lang.Object)
.Default implementation returns false; overridden by data formats that do support native Type Ids. Caller is expected to either use a non-native notation (explicit property or such), or fail, in case it can not use native type ids.
- Returns:
True
if this generator is capable of writing "native" Type Ids (which is typically determined by capabilities of the underlying format),false
if not- Since:
- 2.3
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canWriteBinaryNatively
public boolean canWriteBinaryNatively()Introspection method that may be called to see if the underlying data format supports "native" binary data; that is, an efficient output of binary content without encoding.Default implementation returns false; overridden by data formats that do support native binary content.
- Returns:
True
if this generator is capable of writing "raw" Binary Content (this is typically determined by capabilities of the underlying format);false
if not- Since:
- 2.3
-
canOmitFields
public boolean canOmitFields()Introspection method to call to check whether it is ok to omit writing of Object fields or not. Most formats do allow omission, but certain positional formats (such as CSV) require output of placeholders, even if no real values are to be emitted.- Returns:
True
if this generator is allowed to only write values of some Object fields and omit the rest;false
if not- Since:
- 2.3
-
canWriteFormattedNumbers
public boolean canWriteFormattedNumbers()Introspection method to call to check whether it is possible to write numbers usingwriteNumber(java.lang.String)
using possible custom format, or not. Typically textual formats allow this (and JSON specifically does), whereas binary formats do not allow this (except by writing them as Strings). Usual reason for calling this method is to check whether custom formatting of numbers may be applied by higher-level code (databinding) or not.- Returns:
True
if this generator is capable of writing "formatted" numbers (and if so, need to be passed usingwriteNumber(String)
, that is, passed asString
);false
if not- Since:
- 2.8
-
getWriteCapabilities
Accessor for getting metadata on capabilities of this generator, based on underlying data format being read (directly or indirectly).- Returns:
- Set of write capabilities for content written using this generator
- Since:
- 2.12
-
writeStartArray
Method for writing starting marker of a Array value (for JSON this is character '['; plus possible white space decoration if pretty-printing is enabled).Array values can be written in any context where values are allowed: meaning everywhere except for when a field name is expected.
- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeStartArray
Deprecated.Since 2.12 UsewriteStartArray(Object, int)
insteadMethod for writing start marker of an Array value, similar towriteStartArray()
, but also specifying how many elements will be written for the array before callingwriteEndArray()
.Default implementation simply calls
writeStartArray()
.- Parameters:
size
- Number of elements this array will have: actual number of values written (before matching call towriteEndArray()
MUST match; generator MAY verify this is the case (and SHOULD if format itself encodes length)- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.4
-
writeStartArray
Method for writing start marker of an Array value, similar towriteStartArray()
, but also specifying the "current value" to assign to the new Array context being created.- Parameters:
forValue
- "Current value" to assign for the Array context being created- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.10
-
writeStartArray
Method for writing start marker of an Array value, similar towriteStartArray()
, but also specifying the "current value" to assign to the new Array context being created as well as how many elements will be written for the array before callingwriteEndArray()
.- Parameters:
forValue
- "Current value" to assign for the Array context being createdsize
- Number of elements this Array will have: actual number of values written (before matching call towriteEndArray()
MUST match; generator MAY verify this is the case (and SHOULD if format itself encodes length)- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.10
-
writeEndArray
Method for writing closing marker of a JSON Array value (character ']'; plus possible white space decoration if pretty-printing is enabled).Marker can be written if the innermost structured type is Array.
- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeStartObject
Method for writing starting marker of an Object value (character '{'; plus possible white space decoration if pretty-printing is enabled).Object values can be written in any context where values are allowed: meaning everywhere except for when a field name is expected.
- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeStartObject
Method for writing starting marker of an Object value to represent the given Java Object value. Argument is offered as metadata, but more importantly it should be assigned as the "current value" for the Object content that gets constructed and initialized.Object values can be written in any context where values are allowed: meaning everywhere except for when a field name is expected.
- Parameters:
forValue
- "Current value" to assign for the Object context being created- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.8
-
writeStartObject
Method for writing starting marker of an Object value to represent the given Java Object value. Argument is offered as metadata, but more importantly it should be assigned as the "current value" for the Object content that gets constructed and initialized. In addition, caller knows number of key/value pairs ("properties") that will get written for the Object value: this is relevant for some format backends (but not, as an example, for JSON).Object values can be written in any context where values are allowed: meaning everywhere except for when a field name is expected.
- Parameters:
forValue
- "Current value" to assign for the Object context being createdsize
- Number of key/value pairs this Object will have: actual number of entries written (before matching call towriteEndObject()
MUST match; generator MAY verify this is the case (and SHOULD if format itself encodes length)- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.10
-
writeEndObject
Method for writing closing marker of an Object value (character '}'; plus possible white space decoration if pretty-printing is enabled).Marker can be written if the innermost structured type is Object, and the last written event was either a complete value, or START-OBJECT marker (see JSON specification for more details).
- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeFieldName
Method for writing a field name (JSON String surrounded by double quotes: syntactically identical to a JSON String value), possibly decorated by white space if pretty-printing is enabled.Field names can only be written in Object context (check out JSON specification for details), when field name is expected (field names alternate with values).
- Parameters:
name
- Field name to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeFieldName
Method similar towriteFieldName(String)
, main difference being that it may perform better as some of processing (such as quoting of certain characters, or encoding into external encoding if supported by generator) can be done just once and reused for later calls.Default implementation simple uses unprocessed name container in serialized String; implementations are strongly encouraged to make use of more efficient methods argument object has.
- Parameters:
name
- Field name to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeFieldId
Alternative towriteFieldName(String)
that may be used in cases where property key is of numeric type; either where underlying format supports such notion (some binary formats do, unlike JSON), or for convenient conversion into String presentation. Default implementation will simply convert id intoString
and callwriteFieldName(String)
.- Parameters:
id
- Field id to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.8
-
writeArray
Value write method that can be called to write a single array (sequence ofJsonToken.START_ARRAY
, zero or moreJsonToken.VALUE_NUMBER_INT
,JsonToken.END_ARRAY
)- Parameters:
array
- Array that contains values to writeoffset
- Offset of the first element to write, within arraylength
- Number of elements in array to write, from `offset` to `offset + len - 1`- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.8
-
writeArray
Value write method that can be called to write a single array (sequence ofJsonToken.START_ARRAY
, zero or moreJsonToken.VALUE_NUMBER_INT
,JsonToken.END_ARRAY
)- Parameters:
array
- Array that contains values to writeoffset
- Offset of the first element to write, within arraylength
- Number of elements in array to write, from `offset` to `offset + len - 1`- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.8
-
writeArray
Value write method that can be called to write a single array (sequence ofJsonToken.START_ARRAY
, zero or moreJsonToken.VALUE_NUMBER_FLOAT
,JsonToken.END_ARRAY
)- Parameters:
array
- Array that contains values to writeoffset
- Offset of the first element to write, within arraylength
- Number of elements in array to write, from `offset` to `offset + len - 1`- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.8
-
writeArray
Value write method that can be called to write a single array (sequence ofJsonToken.START_ARRAY
, zero or moreJsonToken.VALUE_STRING
,JsonToken.END_ARRAY
)- Parameters:
array
- Array that contains values to writeoffset
- Offset of the first element to write, within arraylength
- Number of elements in array to write, from `offset` to `offset + len - 1`- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.11
-
writeString
Method for outputting a String value. Depending on context this means either array element, (object) field value or a stand alone String; but in all cases, String will be surrounded in double quotes, and contents will be properly escaped as required by JSON specification.- Parameters:
text
- Text value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeString
Method for outputting a String value. Depending on context this means either array element, (object) field value or a stand alone String; but in all cases, String will be surrounded in double quotes, and contents will be properly escaped as required by JSON specification. Iflen
is < 0, then write all contents of the reader. Otherwise, write only len characters.Note: actual length of content available may exceed
len
but can not be less than it: if not enough content available, aJsonGenerationException
will be thrown.- Parameters:
reader
- Reader to use for reading Text value to writelen
- Maximum Length of Text value to read (inchar
s, non-negative) if known;-1
to indicate "read and write it all"- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer; or if length (len
) is specified butreader
does not provide enough content- Since:
- 2.9
-
writeString
Method for outputting a String value. Depending on context this means either array element, (object) field value or a stand alone String; but in all cases, String will be surrounded in double quotes, and contents will be properly escaped as required by JSON specification.- Parameters:
buffer
- Buffer that contains String value to writeoffset
- Offset inbuffer
of the first character of String value to writelen
- Length of the String value (in characters) to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeString
Method similar towriteString(String)
, but that takesSerializableString
which can make this potentially more efficient to call as generator may be able to reuse quoted and/or encoded representation.Default implementation just calls
writeString(String)
; sub-classes should override it with more efficient implementation if possible.- Parameters:
text
- Pre-encoded String value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeRawUTF8String
Method similar towriteString(String)
but that takes as its input a UTF-8 encoded String that is to be output as-is, without additional escaping (type of which depends on data format; backslashes for JSON). However, quoting that data format requires (like double-quotes for JSON) will be added around the value if and as necessary.Note that some backends may choose not to support this method: for example, if underlying destination is a
Writer
using this method would require UTF-8 decoding. If so, implementation may instead choose to throw aUnsupportedOperationException
due to ineffectiveness of having to decode input.- Parameters:
buffer
- Buffer that contains String value to writeoffset
- Offset inbuffer
of the first byte of String value to writelen
- Length of the String value (in characters) to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeUTF8String
Method similar towriteString(String)
but that takes as its input a UTF-8 encoded String which has not been escaped using whatever escaping scheme data format requires (for JSON that is backslash-escaping for control characters and double-quotes; for other formats something else). This means that textual JSON backends need to check if value needs JSON escaping, but otherwise can just be copied as is to output. Also, quoting that data format requires (like double-quotes for JSON) will be added around the value if and as necessary.Note that some backends may choose not to support this method: for example, if underlying destination is a
Writer
using this method would require UTF-8 decoding. In this case generator implementation may instead choose to throw aUnsupportedOperationException
due to ineffectiveness of having to decode input.- Parameters:
buffer
- Buffer that contains String value to writeoffset
- Offset inbuffer
of the first byte of String value to writelen
- Length of the String value (in characters) to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeRaw
Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, usewriteRawValue(String)
instead.Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw
UnsupportedOperationException
.- Parameters:
text
- Textual contents to include as-is in output.- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeRaw
Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, usewriteRawValue(String)
instead.Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw
UnsupportedOperationException
.- Parameters:
text
- String that has contents to include as-is in outputoffset
- Offset withintext
of the first character to outputlen
- Length of content (fromtext
, starting at offsetoffset
) to output- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeRaw
Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, usewriteRawValue(String)
instead.Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw
UnsupportedOperationException
.- Parameters:
text
- Buffer that has contents to include as-is in outputoffset
- Offset withintext
of the first character to outputlen
- Length of content (fromtext
, starting at offsetoffset
) to output- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeRaw
Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, usewriteRawValue(String)
instead.Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw
UnsupportedOperationException
.- Parameters:
c
- Character to included in output- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeRaw
Method that will force generator to copy input text verbatim with no modifications (including that no escaping is done and no separators are added even if context [array, object] would otherwise require such). If such separators are desired, usewriteRawValue(String)
instead.Note that not all generator implementations necessarily support such by-pass methods: those that do not will throw
UnsupportedOperationException
.The default implementation delegates to
writeRaw(String)
; other backends that support raw inclusion of text are encouraged to implement it in more efficient manner (especially if they use UTF-8 encoding).- Parameters:
raw
- Pre-encoded textual contents to included in output- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeRawValue
Method that will force generator to copy input text verbatim without any modifications, but assuming it must constitute a single legal JSON value (number, string, boolean, null, Array or List). Assuming this, proper separators are added if and as needed (comma or colon), and generator state updated to reflect this.- Parameters:
text
- Textual contents to included in output- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeRawValue
- Throws:
IOException
-
writeRawValue
- Throws:
IOException
-
writeRawValue
Method similar towriteRawValue(String)
, but potentially more efficient as it may be able to use pre-encoded content (similar towriteRaw(SerializableString)
.- Parameters:
raw
- Pre-encoded textual contents to included in output- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.5
-
writeBinary
public abstract void writeBinary(Base64Variant bv, byte[] data, int offset, int len) throws IOException Method that will output given chunk of binary data as base64 encoded, as a complete String value (surrounded by double quotes). This method defaultsNote: because JSON Strings can not contain unescaped linefeeds, if linefeeds are included (as per last argument), they must be escaped. This adds overhead for decoding without improving readability. Alternatively if linefeeds are not included, resulting String value may violate the requirement of base64 RFC which mandates line-length of 76 characters and use of linefeeds. However, all
JsonParser
implementations are required to accept such "long line base64"; as do typical production-level base64 decoders.- Parameters:
bv
- Base64 variant to use: defines details such as whether padding is used (and if so, using which character); what is the maximum line length before adding linefeed, and also the underlying alphabet to use.data
- Buffer that contains binary data to writeoffset
- Offset indata
of the first byte of data to writelen
- Length of data to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeBinary
Similar towriteBinary(Base64Variant,byte[],int,int)
, but default to using the Jackson default Base64 variant (which isBase64Variants.MIME_NO_LINEFEEDS
).- Parameters:
data
- Buffer that contains binary data to writeoffset
- Offset indata
of the first byte of data to writelen
- Length of data to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeBinary
Similar towriteBinary(Base64Variant,byte[],int,int)
, but assumes default to using the Jackson default Base64 variant (which isBase64Variants.MIME_NO_LINEFEEDS
). Also assumes that whole byte array is to be output.- Parameters:
data
- Buffer that contains binary data to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeBinary
Similar towriteBinary(Base64Variant,InputStream,int)
, but assumes default to using the Jackson default Base64 variant (which isBase64Variants.MIME_NO_LINEFEEDS
).- Parameters:
data
- InputStream to use for reading binary data to write. Will not be closed after successful write operationdataLength
- (optional) number of bytes that will be available; or -1 to be indicate it is not known. Note that implementations need not support cases where length is not known in advance; this depends on underlying data format: JSON output does NOT require length, other formats may- Returns:
- Number of bytes actually written
- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeBinary
public abstract int writeBinary(Base64Variant bv, InputStream data, int dataLength) throws IOException Method similar towriteBinary(Base64Variant,byte[],int,int)
, but where input is provided through a stream, allowing for incremental writes without holding the whole input in memory.- Parameters:
bv
- Base64 variant to usedata
- InputStream to use for reading binary data to write. Will not be closed after successful write operationdataLength
- (optional) number of bytes that will be available; or -1 to be indicate it is not known. If a positive length is given,data
MUST provide at least that many bytes: if not, an exception will be thrown. Note that implementations need not support cases where length is not known in advance; this depends on underlying data format: JSON output does NOT require length, other formats may.- Returns:
- Number of bytes read from
data
and written as binary payload - Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumber
Method for outputting given value as JSON number. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.- Parameters:
v
- Number value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.2
-
writeNumber
Method for outputting given value as JSON number. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.- Parameters:
v
- Number value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumber
Method for outputting given value as JSON number. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.- Parameters:
v
- Number value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumber
Method for outputting given value as JSON number. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.- Parameters:
v
- Number value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumber
Method for outputting indicate JSON numeric value. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.- Parameters:
v
- Number value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumber
Method for outputting indicate JSON numeric value. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.- Parameters:
v
- Number value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumber
Method for outputting indicate JSON numeric value. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.- Parameters:
v
- Number value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumber
Write method that can be used for custom numeric types that can not be (easily?) converted to "standard" Java number types. Because numbers are not surrounded by double quotes, regularwriteString(java.lang.String)
method can not be used; norwriteRaw(java.lang.String)
because that does not properly handle value separators needed in Array or Object contexts.Note: because of lack of type safety, some generator implementations may not be able to implement this method. For example, if a binary JSON format is used, it may require type information for encoding; similarly for generator-wrappers around Java objects or JSON nodes. If implementation does not implement this method, it needs to throw
UnsupportedOperationException
.- Parameters:
encodedValue
- Textual (possibly format) number representation to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layerUnsupportedOperationException
- If underlying data format does not support numbers serialized textually AND if generator is not allowed to just output a String instead (Schema-based formats may require actual number, for example)
-
writeNumber
Overloaded version ofwriteNumber(String)
with same semantics but possibly more efficient operation.- Parameters:
encodedValueBuffer
- Buffer that contains the textual number representation to writeoffset
- Offset of the first character of value to writelen
- Length of the value (in characters) to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.11
-
writeBoolean
Method for outputting literal JSON boolean value (one of Strings 'true' and 'false'). Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.- Parameters:
state
- Boolean value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNull
Method for outputting literal JSON null value. Can be called in any context where a value is expected (Array value, Object field value, root-level value). Additional white space may be added around the value if pretty-printing is enabled.- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeEmbeddedObject
Method that can be called on backends that support passing opaque native values that some data formats support; not used with JSON backend, more common with binary formats.NOTE: this is NOT the method to call for serializing regular POJOs, see
writeObject(java.lang.Object)
instead.- Parameters:
object
- Native format-specific value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.8
-
writeObjectId
Method that can be called to output so-called native Object Id. Note that it may only be called after ensuring this is legal (withcanWriteObjectId()
), as not all data formats have native type id support; and some may only allow them in certain positions or locations. If output is not allowed by the data format in this position, aJsonGenerationException
will be thrown.- Parameters:
id
- Native Object Id to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layerJsonGenerationException
- if Object ID output is not allowed (either at all, or specifically in this position in output)- Since:
- 2.3
-
writeObjectRef
Method that can be called to output references to native Object Ids. Note that it may only be called after ensuring this is legal (withcanWriteObjectId()
), as not all data formats have native type id support; and some may only allow them in certain positions or locations. If output is not allowed by the data format in this position, aJsonGenerationException
will be thrown.- Parameters:
referenced
- Referenced value, for which Object Id is expected to be written- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layerJsonGenerationException
- if Object ID output is not allowed (either at all, or specifically in this position in output)
-
writeTypeId
Method that can be called to output so-called native Type Id. Note that it may only be called after ensuring this is legal (withcanWriteTypeId()
), as not all data formats have native type id support; and some may only allow them in certain positions or locations. If output is not allowed by the data format in this position, aJsonGenerationException
will be thrown.- Parameters:
id
- Native Type Id to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layerJsonGenerationException
- if Type ID output is not allowed (either at all, or specifically in this position in output)- Since:
- 2.3
-
writeTypePrefix
Replacement method forwriteTypeId(Object)
which is called regardless of whether format has native type ids. If it does have native type ids, those are to be used (if configuration allows this), if not, structural type id inclusion is to be used. For JSON, for example, no native type ids exist and structural inclusion is always used.NOTE: databind may choose to skip calling this method for some special cases (and instead included type id via regular write methods and/or
writeTypeId(java.lang.Object)
-- this is discouraged, but not illegal, and may be necessary as a work-around in some cases.- Parameters:
typeIdDef
- Full Type Id definition- Returns:
WritableTypeId
for caller to retain and pass to matchingwriteTypeSuffix(com.fasterxml.jackson.core.type.WritableTypeId)
call- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layerJsonGenerationException
- if Type ID output is not allowed (either at all, or specifically in this position in output)- Since:
- 2.9
-
writeTypeSuffix
Method to call along withwriteTypePrefix(com.fasterxml.jackson.core.type.WritableTypeId)
, but after actual value that has type id has been completely written. This allows post-processing for some cases (for example if the actual Type Id is written at the END of the value, not before or at the beginning).- Parameters:
typeIdDef
- Value returned by the earlier matching call towriteTypePrefix(WritableTypeId)
- Returns:
- Argument
typeIdDef
, possibly modified - Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layerJsonGenerationException
- if Type ID output is not allowed (either at all, or specifically in this position in output)- Since:
- 2.9
-
writePOJO
Method for writing given Java object (POJO) as JSON. Exactly how the object gets written depends on object in question (and on codec, its configuration); for typical POJOs it will result in JSON Object, but for others JSON Array, or String or numeric value (and for nulls, JSON null literal). NOTE: generator must have itsObjectCodec
set to non-null value; for generators created by a mapping factory this is the case, for others not.- Parameters:
pojo
- Java value (usually POJO) to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.13 (to eventually replace
writeObject(Object)
-
writeObject
Older alias forwritePOJO(Object)
- Parameters:
pojo
- Java value (usually POJO) to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeTree
Method for writing given JSON tree (expressed as a tree where given JsonNode is the root) using this generator. This will generally just callwriteObject(java.lang.Object)
with given node, but is added for convenience and to make code more explicit in cases where it deals specifically with trees.- Parameters:
rootNode
-TreeNode
to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeBinaryField
Convenience method for outputting a field entry ("member") that contains specified data in base64-encoded form. Equivalent to:writeFieldName(fieldName); writeBinary(value);
- Parameters:
fieldName
- Name of the field to writedata
- Binary data for the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeBooleanField
Convenience method for outputting a field entry ("member") that has a boolean value. Equivalent to:writeFieldName(fieldName); writeBoolean(value);
- Parameters:
fieldName
- Name of the field to writevalue
- Boolean value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNullField
Convenience method for outputting a field entry ("member") that has JSON literal value null. Equivalent to:writeFieldName(fieldName); writeNull();
- Parameters:
fieldName
- Name of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeStringField
Convenience method for outputting a field entry ("member") that has a String value. Equivalent to:writeFieldName(fieldName); writeString(value);
- Parameters:
fieldName
- Name of the field to writevalue
- String value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumberField
Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to:writeFieldName(fieldName); writeNumber(value);
- Parameters:
fieldName
- Name of the field to writevalue
- Numeric value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.11
-
writeNumberField
Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to:writeFieldName(fieldName); writeNumber(value);
- Parameters:
fieldName
- Name of the field to writevalue
- Numeric value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumberField
Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to:writeFieldName(fieldName); writeNumber(value);
- Parameters:
fieldName
- Name of the field to writevalue
- Numeric value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumberField
Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to:writeFieldName(fieldName); writeNumber(value);
- Parameters:
fieldName
- Name of the field to writevalue
- Numeric value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.11
-
writeNumberField
Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to:writeFieldName(fieldName); writeNumber(value);
- Parameters:
fieldName
- Name of the field to writevalue
- Numeric value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumberField
Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to:writeFieldName(fieldName); writeNumber(value);
- Parameters:
fieldName
- Name of the field to writevalue
- Numeric value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeNumberField
Convenience method for outputting a field entry ("member") that has the specified numeric value. Equivalent to:writeFieldName(fieldName); writeNumber(value);
- Parameters:
fieldName
- Name of the field to writevalue
- Numeric value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeArrayFieldStart
Convenience method for outputting a field entry ("member") (that will contain a JSON Array value), and the START_ARRAY marker. Equivalent to:writeFieldName(fieldName); writeStartArray();
Note: caller still has to take care to close the array (by calling {#link #writeEndArray}) after writing all values of the value Array.
- Parameters:
fieldName
- Name of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeObjectFieldStart
Convenience method for outputting a field entry ("member") (that will contain an Object value), and the START_OBJECT marker. Equivalent to:writeFieldName(fieldName); writeStartObject();
Note: caller still has to take care to close the Object (by calling {#link #writeEndObject}) after writing all entries of the value Object.
- Parameters:
fieldName
- Name of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writePOJOField
Convenience method for outputting a field entry ("member") that has contents of specific Java object as its value. Equivalent to:writeFieldName(fieldName); writeObject(pojo);
NOTE: actual serialization of POJO value requires assigned
ObjectCodec
and will delegate to that (usuallyObjectMapper
of databind layer)- Parameters:
fieldName
- Name of the field to writepojo
- POJO value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeObjectField
Older alias forwritePOJOField(java.lang.String, java.lang.Object)
- Parameters:
fieldName
- Name of the field to writepojo
- POJO value of the field to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
writeOmittedField
Method called to indicate that a property in this position was skipped. It is usually only called for generators that returnfalse
fromcanOmitFields()
.Default implementation does nothing.
- Parameters:
fieldName
- Name of the field omitted- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.3
-
copyCurrentEvent
Method for copying contents of the current event that the given parser instance points to. Note that the method will not copy any other events, such as events contained within JSON Array or Object structures.Calling this method will not advance the given parser, although it may cause parser to internally process more data (if it lazy loads contents of value events, for example)
- Parameters:
p
- Parser that points to event (token) to copy- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
copyCurrentEventExact
Same ascopyCurrentEvent(com.fasterxml.jackson.core.JsonParser)
with the exception that copying of numeric values tries to avoid any conversion losses; in particular for floating-point numbers. This usually matters when transcoding from textual format like JSON to a binary format. See_copyCurrentFloatValueExact(com.fasterxml.jackson.core.JsonParser)
for details.- Parameters:
p
- Parser that points to event (token) to copy- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer- Since:
- 2.15
-
copyCurrentStructure
Method for copying contents of the current event and following events that it encloses the given parser instance points to.So what constitutes enclosing? Here is the list of events that have associated enclosed events that will get copied:
JsonToken.START_OBJECT
: all events up to and including matching (closing)JsonToken.END_OBJECT
will be copiedJsonToken.START_ARRAY
all events up to and including matching (closing)JsonToken.END_ARRAY
will be copiedJsonToken.FIELD_NAME
the logical value (which can consist of a single scalar value; or a sequence of related events for structured types (JSON Arrays, Objects)) will be copied along with the name itself. So essentially the whole field entry (name and value) will be copied.
After calling this method, parser will point to the last event that was copied. This will either be the event parser already pointed to (if there were no enclosed events), or the last enclosed event copied.
NOTE: copying of individual tokens/events is handled by delegating to
copyCurrentEvent(com.fasterxml.jackson.core.JsonParser)
method (make sure to read about difference between that method andcopyCurrentEventExact(com.fasterxml.jackson.core.JsonParser)
for numeric value accuracy).- Parameters:
p
- Parser that points to the value to copy- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
_copyCurrentContents
- Throws:
IOException
-
_copyCurrentFloatValue
Method for copying currentJsonToken.VALUE_NUMBER_FLOAT
value; overridable by format backend implementations. Implementation checksJsonParser.getNumberType()
for declared type and uses matching accessors: this may cause inexact conversion for some textual formats (depending on settings). If this is problematic, use instead (note that doing so may add overhead).- Parameters:
p
- Parser that points to the value to copy- Throws:
IOException
- Since:
- 2.15
-
_copyCurrentFloatValueExact
Method for copying currentJsonToken.VALUE_NUMBER_FLOAT
value; overridable by format backend implementations. Implementation ensures it uses most accurate accessors necessary to retain exact value in case of possible numeric conversion: in practice this means thatBigDecimal
is usually used as the representation accessed fromJsonParser
, regardless of whetherDouble
might be accurate (since detecting lossy conversion is not possible to do efficiently). If minimal overhead is desired, use_copyCurrentFloatValue(com.fasterxml.jackson.core.JsonParser)
instead.- Parameters:
p
- Parser that points to the value to copy- Throws:
IOException
- Since:
- 2.15
-
_copyCurrentIntValue
Method for copying currentJsonToken.VALUE_NUMBER_FLOAT
value; overridable by format backend implementations.- Parameters:
p
- Parser that points to the value to copy- Throws:
IOException
- Since:
- 2.15
-
_copyCurrentStringValue
Method for copying currentJsonToken.VALUE_STRING
value; overridable by format backend implementations.- Parameters:
p
- Parser that points to the value to copy- Throws:
IOException
- Since:
- 2.15
-
flush
Method called to flush any buffered content to the underlying target (output stream, writer), and to flush the target itself as well.- Specified by:
flush
in interfaceFlushable
- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
isClosed
public abstract boolean isClosed()Method that can be called to determine whether this generator is closed or not. If it is closed, no more output can be done.- Returns:
True
if this generator instance has been closed
-
close
Method called to close this generator, so that no more content can be written.Whether the underlying target (stream, writer) gets closed depends on whether this generator either manages the target (i.e. is the only one with access to the target -- case if caller passes a reference to the resource such as File, but not stream); or has feature
JsonGenerator.Feature.AUTO_CLOSE_TARGET
enabled. If either of above is true, the target is also closed. Otherwise (not managing, feature not enabled), target is not closed.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Throws:
IOException
- if there is either an underlying I/O problem
-
_reportError
Helper method used for constructing and throwingJsonGenerationException
with given base message.Note that sub-classes may override this method to add more detail or use a
JsonGenerationException
sub-class.- Parameters:
msg
- Exception message to use- Throws:
JsonGenerationException
- constructed
-
_throwInternal
protected final void _throwInternal() -
_reportUnsupportedOperation
protected void _reportUnsupportedOperation() -
_verifyOffsets
protected final void _verifyOffsets(int arrayLength, int offset, int length) -
_writeSimpleObject
Helper method to try to call appropriate write method for given untyped Object. At this point, no structural conversions should be done, only simple basic types are to be coerced as necessary.- Parameters:
value
- Value to write- Throws:
IOException
- if there is either an underlying I/O problem or encoding issue at format layer
-
overrideStdFeatures(int, int)
instead -- remove from 2.9