com.fasterxml.jackson.core
Class JsonFactory

java.lang.Object
  com.fasterxml.jackson.core.JsonFactory

All Implemented Interfaces:

Versioned

public class JsonFactory
extends Object
implements Versioned

The main factory class of Jackson package, used to configure and construct reader (aka parser, JsonParser) and writer (aka generator, JsonGenerator) instances.

Factory instances are thread-safe and reusable after configuration (if any). Typically applications and services use only a single globally shared factory instance, unless they need differently configured factories. Factory reuse is important if efficiency matters; most recycling of expensive construct is done on per-factory basis.

Creation of a factory instance is a light-weight operation, and since there is no need for pluggable alternative implementations (as there is no "standard" JSON processor API to implement), the default constructor is used for constructing factory instances.

Author:

Tatu Saloranta

Nested Class Summary

static class

JsonFactory.Feature Enumeration that defines all on/off features that can only be changed for JsonFactory.

Field Summary

protected CharacterEscapes	_characterEscapes Definition of custom character escapes to use for generators created by this factory, if any.
protected int	_factoryFeatures Currently enabled factory features.
protected int	_generatorFeatures Currently enabled generator features.
protected InputDecorator	_inputDecorator Optional helper object that may decorate input sources, to do additional processing on input during parsing.
protected ObjectCodec	_objectCodec Object that implements conversion functionality between Java objects and JSON content.
protected OutputDecorator	_outputDecorator Optional helper object that may decorate output object, to do additional processing on output during content generation.
protected int	_parserFeatures Currently enabled parser features.
protected static ThreadLocal<SoftReference<BufferRecycler>>	_recyclerRef This ThreadLocal contains a SoftRerefence to a BufferRecycler used to provide a low-cost buffer recycling between reader and writer instances.
protected BytesToNameCanonicalizer	_rootByteSymbols Alternative to the basic symbol table, some stream-based parsers use different name canonicalization method.
protected CharsToNameCanonicalizer	_rootCharSymbols Each factory comes equipped with a shared root symbol table.
protected static int	DEFAULT_FACTORY_FEATURE_FLAGS Bitfield (set of flags) of all factory features that are enabled by default.
protected static int	DEFAULT_GENERATOR_FEATURE_FLAGS Bitfield (set of flags) of all generator features that are enabled by default.
protected static int	DEFAULT_PARSER_FEATURE_FLAGS Bitfield (set of flags) of all parser features that are enabled by default.
static String	FORMAT_NAME_JSON Name used to identify JSON format (and returned by getFormatName()

Constructor Summary

JsonFactory()
Default constructor used to create factory instances.

JsonFactory(ObjectCodec oc)

Method Summary

protected IOContext	_createContext(Object srcRef, boolean resourceManaged) Overridable factory method that actually instantiates desired context object.
protected JsonGenerator	_createJsonGenerator(Writer out, IOContext ctxt) Overridable factory method that actually instantiates generator for given Writer and context object.
protected JsonParser	_createJsonParser(byte[] data, int offset, int len, IOContext ctxt) Overridable factory method that actually instantiates parser using given Reader object for reading content passed as raw byte array.
protected JsonParser	_createJsonParser(InputStream in, IOContext ctxt) Overridable factory method that actually instantiates desired parser given InputStream and context object.
protected JsonParser	_createJsonParser(Reader r, IOContext ctxt) Overridable factory method that actually instantiates parser using given Reader object for reading content.
protected JsonGenerator	_createUTF8JsonGenerator(OutputStream out, IOContext ctxt) Overridable factory method that actually instantiates generator for given OutputStream and context object, using UTF-8 encoding.
protected Writer	_createWriter(OutputStream out, JsonEncoding enc, IOContext ctxt)
BufferRecycler	_getBufferRecycler() Method used by factory to create buffer recycler instances for parsers and generators.
protected InputStream	_optimizedStreamFromURL(URL url) Helper methods used for constructing an optimal stream for parsers to use, when input is to be read from an URL.
JsonFactory	configure(JsonFactory.Feature f, boolean state) Method for enabling or disabling specified parser feature (check JsonParser.Feature for list of features)
JsonFactory	configure(JsonGenerator.Feature f, boolean state) Method for enabling or disabling specified generator feature (check JsonGenerator.Feature for list of features)
JsonFactory	configure(JsonParser.Feature f, boolean state) Method for enabling or disabling specified parser feature (check JsonParser.Feature for list of features)
JsonGenerator	createJsonGenerator(File f, JsonEncoding enc) Method for constructing JSON generator for writing JSON content to specified file, overwriting contents it might have (or creating it if such file does not yet exist).
JsonGenerator	createJsonGenerator(OutputStream out) Convenience method for constructing generator that uses default encoding of the format (UTF-8 for JSON and most other data formats).
JsonGenerator	createJsonGenerator(OutputStream out, JsonEncoding enc) Method for constructing JSON generator for writing JSON content using specified output stream.
JsonGenerator	createJsonGenerator(Writer out) Method for constructing JSON generator for writing JSON content using specified Writer.
JsonParser	createJsonParser(byte[] data) Method for constructing parser for parsing the contents of given byte array.
JsonParser	createJsonParser(byte[] data, int offset, int len) Method for constructing parser for parsing the contents of given byte array.
JsonParser	createJsonParser(File f) Method for constructing JSON parser instance to parse contents of specified file.
JsonParser	createJsonParser(InputStream in) Method for constructing JSON parser instance to parse the contents accessed via specified input stream.
JsonParser	createJsonParser(Reader r) Method for constructing parser for parsing the contents accessed via specified Reader.
JsonParser	createJsonParser(String content) Method for constructing parser for parsing contents of given String.
JsonParser	createJsonParser(URL url) Method for constructing JSON parser instance to parse contents of resource reference by given URL.
JsonFactory	disable(JsonFactory.Feature f) Method for disabling specified parser features (check JsonFactory.Feature for list of features)
JsonFactory	disable(JsonGenerator.Feature f) Method for disabling specified generator feature (check JsonGenerator.Feature for list of features)
JsonFactory	disable(JsonParser.Feature f) Method for disabling specified parser features (check JsonParser.Feature for list of features)
JsonFactory	enable(JsonFactory.Feature f) Method for enabling specified parser feature (check JsonFactory.Feature for list of features)
JsonFactory	enable(JsonGenerator.Feature f) Method for enabling specified generator features (check JsonGenerator.Feature for list of features)
JsonFactory	enable(JsonParser.Feature f) Method for enabling specified parser feature (check JsonParser.Feature for list of features)
CharacterEscapes	getCharacterEscapes() Method for accessing custom escapes factory uses for JsonGenerators it creates.
ObjectCodec	getCodec()
String	getFormatName() Method that returns short textual id identifying format this factory supports.
InputDecorator	getInputDecorator() Method for getting currently configured input decorator (if any; there is no default decorator).
OutputDecorator	getOutputDecorator() Method for getting currently configured output decorator (if any; there is no default decorator).
MatchStrength	hasFormat(InputAccessor acc)
protected MatchStrength	hasJSONFormat(InputAccessor acc)
boolean	isEnabled(JsonFactory.Feature f) Checked whether specified parser feature is enabled.
boolean	isEnabled(JsonGenerator.Feature f) Check whether specified generator feature is enabled.
boolean	isEnabled(JsonParser.Feature f) Checked whether specified parser feature is enabled.
JsonFactory	setCharacterEscapes(CharacterEscapes esc) Method for defining custom escapes factory uses for JsonGenerators it creates.
JsonFactory	setCodec(ObjectCodec oc) Method for associating a ObjectCodec (typically a com.fasterxml.jackson.databind.ObjectMapper) with this factory (and more importantly, parsers and generators it constructs).
JsonFactory	setInputDecorator(InputDecorator d) Method for overriding currently configured input decorator
JsonFactory	setOutputDecorator(OutputDecorator d) Method for overriding currently configured output decorator
Version	version() Method called to detect version of the component that implements this interface; returned version should never be null, but may return specific "not available" instance (see Version for details).

Methods inherited from class java.lang.Object

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

Field Detail

FORMAT_NAME_JSON

public static final String FORMAT_NAME_JSON

Name used to identify JSON format (and returned by getFormatName()

See Also:

Constant Field Values

DEFAULT_FACTORY_FEATURE_FLAGS

protected static final int DEFAULT_FACTORY_FEATURE_FLAGS

Bitfield (set of flags) of all factory features that are enabled by default.

DEFAULT_PARSER_FEATURE_FLAGS

protected static final int DEFAULT_PARSER_FEATURE_FLAGS

Bitfield (set of flags) of all parser features that are enabled by default.

DEFAULT_GENERATOR_FEATURE_FLAGS

protected static final int DEFAULT_GENERATOR_FEATURE_FLAGS

Bitfield (set of flags) of all generator features that are enabled by default.

_recyclerRef

protected static final ThreadLocal<SoftReference<BufferRecycler>> _recyclerRef

This ThreadLocal contains a SoftRerefence to a BufferRecycler used to provide a low-cost buffer recycling between reader and writer instances.

_rootCharSymbols

protected CharsToNameCanonicalizer _rootCharSymbols

Each factory comes equipped with a shared root symbol table. It should not be linked back to the original blueprint, to avoid contents from leaking between factories.

_rootByteSymbols

protected BytesToNameCanonicalizer _rootByteSymbols

Alternative to the basic symbol table, some stream-based parsers use different name canonicalization method.

TODO: should clean up this; looks messy having 2 alternatives with not very clear differences.

_objectCodec

protected ObjectCodec _objectCodec

Object that implements conversion functionality between Java objects and JSON content. For base JsonFactory implementation usually not set by default, but can be explicitly set. Sub-classes (like @link org.codehaus.jackson.map.MappingJsonFactory} usually provide an implementation.

_factoryFeatures

protected int _factoryFeatures

Currently enabled factory features.

_parserFeatures

protected int _parserFeatures

Currently enabled parser features.

_generatorFeatures

protected int _generatorFeatures

Currently enabled generator features.

_characterEscapes

protected CharacterEscapes _characterEscapes

Definition of custom character escapes to use for generators created by this factory, if any. If null, standard data format specific escapes are used.

_inputDecorator

protected InputDecorator _inputDecorator

Optional helper object that may decorate input sources, to do additional processing on input during parsing.

_outputDecorator

protected OutputDecorator _outputDecorator

Optional helper object that may decorate output object, to do additional processing on output during content generation.

Constructor Detail

JsonFactory

public JsonFactory()

Default constructor used to create factory instances. Creation of a factory instance is a light-weight operation, but it is still a good idea to reuse limited number of factory instances (and quite often just a single instance): factories are used as context for storing some reused processing objects (such as symbol tables parsers use) and this reuse only works within context of a single factory instance.

JsonFactory

public JsonFactory(ObjectCodec oc)

Method Detail

getFormatName

public String getFormatName()

Method that returns short textual id identifying format this factory supports.

Note: sub-classes should override this method; default implementation will return null for all sub-classes

hasFormat

public MatchStrength hasFormat(InputAccessor acc)
                        throws IOException

Throws:

IOException

hasJSONFormat

protected MatchStrength hasJSONFormat(InputAccessor acc)
                               throws IOException

Throws:

IOException

version

public Version version()

Description copied from interface: Versioned

Method called to detect version of the component that implements this interface; returned version should never be null, but may return specific "not available" instance (see Version for details).

Specified by:

version in interface Versioned

configure

public final JsonFactory configure(JsonFactory.Feature f,
                                   boolean state)

Method for enabling or disabling specified parser feature (check JsonParser.Feature for list of features)

enable

public JsonFactory enable(JsonFactory.Feature f)

Method for enabling specified parser feature (check JsonFactory.Feature for list of features)

disable

public JsonFactory disable(JsonFactory.Feature f)

Method for disabling specified parser features (check JsonFactory.Feature for list of features)

isEnabled

public final boolean isEnabled(JsonFactory.Feature f)

Checked whether specified parser feature is enabled.

configure

public final JsonFactory configure(JsonParser.Feature f,
                                   boolean state)

Method for enabling or disabling specified parser feature (check JsonParser.Feature for list of features)

enable

public JsonFactory enable(JsonParser.Feature f)

Method for enabling specified parser feature (check JsonParser.Feature for list of features)

disable

public JsonFactory disable(JsonParser.Feature f)

Method for disabling specified parser features (check JsonParser.Feature for list of features)

isEnabled

public final boolean isEnabled(JsonParser.Feature f)

Checked whether specified parser feature is enabled.

getInputDecorator

public InputDecorator getInputDecorator()

Method for getting currently configured input decorator (if any; there is no default decorator).

setInputDecorator

public JsonFactory setInputDecorator(InputDecorator d)

Method for overriding currently configured input decorator

configure

public final JsonFactory configure(JsonGenerator.Feature f,
                                   boolean state)

Method for enabling or disabling specified generator feature (check JsonGenerator.Feature for list of features)

enable

public JsonFactory enable(JsonGenerator.Feature f)

Method for enabling specified generator features (check JsonGenerator.Feature for list of features)

disable

public JsonFactory disable(JsonGenerator.Feature f)

Method for disabling specified generator feature (check JsonGenerator.Feature for list of features)

isEnabled

public final boolean isEnabled(JsonGenerator.Feature f)

Check whether specified generator feature is enabled.

getCharacterEscapes

public CharacterEscapes getCharacterEscapes()

Method for accessing custom escapes factory uses for JsonGenerators it creates.

setCharacterEscapes

public JsonFactory setCharacterEscapes(CharacterEscapes esc)

Method for defining custom escapes factory uses for JsonGenerators it creates.

getOutputDecorator

public OutputDecorator getOutputDecorator()

Method for getting currently configured output decorator (if any; there is no default decorator).

setOutputDecorator

public JsonFactory setOutputDecorator(OutputDecorator d)

Method for overriding currently configured output decorator

setCodec

public JsonFactory setCodec(ObjectCodec oc)

Method for associating a ObjectCodec (typically a com.fasterxml.jackson.databind.ObjectMapper) with this factory (and more importantly, parsers and generators it constructs). This is needed to use data-binding methods of JsonParser and JsonGenerator instances.

getCodec

public ObjectCodec getCodec()

createJsonParser

public JsonParser createJsonParser(File f)
                            throws IOException,
                                   JsonParseException

Method for constructing JSON parser instance to parse contents of specified file. Encoding is auto-detected from contents according to JSON specification recommended mechanism.

Underlying input stream (needed for reading contents) will be owned (and managed, i.e. closed as need be) by the parser, since caller has no access to it.

Parameters:

f - File that contains JSON content to parse

Throws:

IOException

JsonParseException

createJsonParser

public JsonParser createJsonParser(URL url)
                            throws IOException,
                                   JsonParseException

Method for constructing JSON parser instance to parse contents of resource reference by given URL. Encoding is auto-detected from contents according to JSON specification recommended mechanism.

Underlying input stream (needed for reading contents) will be owned (and managed, i.e. closed as need be) by the parser, since caller has no access to it.

Parameters:

url - URL pointing to resource that contains JSON content to parse

Throws:

IOException

JsonParseException

createJsonParser

public JsonParser createJsonParser(InputStream in)
                            throws IOException,
                                   JsonParseException

Method for constructing JSON parser instance to parse the contents accessed via specified input stream.

The input stream will not be owned by the parser, it will still be managed (i.e. closed if end-of-stream is reacher, or parser close method called) if (and only if) JsonParser.Feature.AUTO_CLOSE_SOURCE is enabled.

Note: no encoding argument is taken since it can always be auto-detected as suggested by Json RFC.

Parameters:

in - InputStream to use for reading JSON content to parse

Throws:

IOException

JsonParseException

createJsonParser

public JsonParser createJsonParser(Reader r)
                            throws IOException,
                                   JsonParseException

Method for constructing parser for parsing the contents accessed via specified Reader.

The read stream will not be owned by the parser, it will still be managed (i.e. closed if end-of-stream is reacher, or parser close method called) if (and only if) JsonParser.Feature.AUTO_CLOSE_SOURCE is enabled.

Parameters:

r - Reader to use for reading JSON content to parse

Throws:

IOException

JsonParseException

createJsonParser

public JsonParser createJsonParser(byte[] data)
                            throws IOException,
                                   JsonParseException

Method for constructing parser for parsing the contents of given byte array.

Throws:

IOException

JsonParseException

createJsonParser

public JsonParser createJsonParser(byte[] data,
                                   int offset,
                                   int len)
                            throws IOException,
                                   JsonParseException

Method for constructing parser for parsing the contents of given byte array.

Parameters:

data - Buffer that contains data to parse

offset - Offset of the first data byte within buffer

len - Length of contents to parse within buffer

Throws:

IOException

JsonParseException

createJsonParser

public JsonParser createJsonParser(String content)
                            throws IOException,
                                   JsonParseException

Method for constructing parser for parsing contents of given String.

Throws:

IOException

JsonParseException

createJsonGenerator

public JsonGenerator createJsonGenerator(OutputStream out,
                                         JsonEncoding enc)
                                  throws IOException

Method for constructing JSON generator for writing JSON content using specified output stream. Encoding to use must be specified, and needs to be one of available types (as per JSON specification).

Underlying stream is NOT owned by the generator constructed, so that generator will NOT close the output stream when JsonGenerator.close() is called (unless auto-closing feature, JsonGenerator.Feature.AUTO_CLOSE_TARGET is enabled). Using application needs to close it explicitly if this is the case.

Note: there are formats that use fixed encoding (like most binary data formats) and that ignore passed in encoding.

Parameters:

out - OutputStream to use for writing JSON content

enc - Character encoding to use

Throws:

IOException

createJsonGenerator

public JsonGenerator createJsonGenerator(Writer out)
                                  throws IOException

Method for constructing JSON generator for writing JSON content using specified Writer.

Underlying stream is NOT owned by the generator constructed, so that generator will NOT close the Reader when JsonGenerator.close() is called (unless auto-closing feature, JsonGenerator.Feature.AUTO_CLOSE_TARGET is enabled). Using application needs to close it explicitly.

Parameters:

out - Writer to use for writing JSON content

Throws:

IOException

createJsonGenerator

public JsonGenerator createJsonGenerator(OutputStream out)
                                  throws IOException

Convenience method for constructing generator that uses default encoding of the format (UTF-8 for JSON and most other data formats).

Note: there are formats that use fixed encoding (like most binary data formats).

Throws:

IOException

createJsonGenerator

public JsonGenerator createJsonGenerator(File f,
                                         JsonEncoding enc)
                                  throws IOException

Method for constructing JSON generator for writing JSON content to specified file, overwriting contents it might have (or creating it if such file does not yet exist). Encoding to use must be specified, and needs to be one of available types (as per JSON specification).

Underlying stream is owned by the generator constructed, i.e. generator will handle closing of file when JsonGenerator.close() is called.

Parameters:

f - File to write contents to

enc - Character encoding to use

Throws:

IOException

_createJsonParser

protected JsonParser _createJsonParser(InputStream in,
                                       IOContext ctxt)
                                throws IOException,
                                       JsonParseException

Overridable factory method that actually instantiates desired parser given InputStream and context object.

This method is specifically designed to remain compatible between minor versions so that sub-classes can count on it being called as expected. That is, it is part of official interface from sub-class perspective, although not a public method available to users of factory implementations.

Throws:

IOException

JsonParseException

_createJsonParser

protected JsonParser _createJsonParser(Reader r,
                                       IOContext ctxt)
                                throws IOException,
                                       JsonParseException

Overridable factory method that actually instantiates parser using given Reader object for reading content.

This method is specifically designed to remain compatible between minor versions so that sub-classes can count on it being called as expected. That is, it is part of official interface from sub-class perspective, although not a public method available to users of factory implementations.

Throws:

IOException

JsonParseException

_createJsonParser

protected JsonParser _createJsonParser(byte[] data,
                                       int offset,
                                       int len,
                                       IOContext ctxt)
                                throws IOException,
                                       JsonParseException

Overridable factory method that actually instantiates parser using given Reader object for reading content passed as raw byte array.

This method is specifically designed to remain compatible between minor versions so that sub-classes can count on it being called as expected. That is, it is part of official interface from sub-class perspective, although not a public method available to users of factory implementations.

Throws:

IOException

JsonParseException

_createJsonGenerator

protected JsonGenerator _createJsonGenerator(Writer out,
                                             IOContext ctxt)
                                      throws IOException

Overridable factory method that actually instantiates generator for given Writer and context object.

This method is specifically designed to remain compatible between minor versions so that sub-classes can count on it being called as expected. That is, it is part of official interface from sub-class perspective, although not a public method available to users of factory implementations.

Throws:

IOException

_createUTF8JsonGenerator

protected JsonGenerator _createUTF8JsonGenerator(OutputStream out,
                                                 IOContext ctxt)
                                          throws IOException

Overridable factory method that actually instantiates generator for given OutputStream and context object, using UTF-8 encoding.

This method is specifically designed to remain compatible between minor versions so that sub-classes can count on it being called as expected. That is, it is part of official interface from sub-class perspective, although not a public method available to users of factory implementations.

Throws:

IOException

_createWriter

protected Writer _createWriter(OutputStream out,
                               JsonEncoding enc,
                               IOContext ctxt)
                        throws IOException

Throws:

IOException

_createContext

protected IOContext _createContext(Object srcRef,
                                   boolean resourceManaged)

Overridable factory method that actually instantiates desired context object.

_getBufferRecycler

public BufferRecycler _getBufferRecycler()

Method used by factory to create buffer recycler instances for parsers and generators.

Note: only public to give access for ObjectMapper

_optimizedStreamFromURL

protected InputStream _optimizedStreamFromURL(URL url)
                                       throws IOException

Helper methods used for constructing an optimal stream for parsers to use, when input is to be read from an URL. This helps when reading file content via URL.

Throws:

IOException