org.codehaus.jackson
Class JsonFactory

java.lang.Object
  extended by org.codehaus.jackson.JsonFactory
All Implemented Interfaces:
Versioned
Direct Known Subclasses:
MappingJsonFactory, SmileFactory

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

Field Summary
protected  int _generatorFeatures
           
protected  ObjectCodec _objectCodec
          Object that implements conversion functionality between Java objects and JSON content.
protected  int _parserFeatures
           
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.
 
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 desired generator.
protected  JsonParser _createJsonParser(byte[] data, int offset, int len, IOContext ctxt)
          Overridable factory method that actually instantiates desired parser.
protected  JsonParser _createJsonParser(InputStream in, IOContext ctxt)
          Overridable factory method that actually instantiates desired parser.
protected  JsonParser _createJsonParser(Reader r, IOContext ctxt)
          Overridable factory method that actually instantiates desired parser.
protected  JsonGenerator _createUTF8JsonGenerator(OutputStream out, IOContext ctxt)
          Overridable factory method that actually instantiates desired generator that is specifically to output content using specified output stream and 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(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, 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)
           
 JsonParser createJsonParser(byte[] data, int offset, int len)
           
 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 json parser instance to parse the contents accessed via specified Reader.
 JsonParser createJsonParser(String content)
           
 JsonParser createJsonParser(URL url)
          Method for constructing json parser instance to parse contents of resource reference by given URL.
 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)
 void disableGeneratorFeature(JsonGenerator.Feature f)
          Deprecated. Use disable(JsonGenerator.Feature) instead
 void disableParserFeature(JsonParser.Feature f)
          Deprecated. Use disable(JsonParser.Feature) instead
 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)
 void enableGeneratorFeature(JsonGenerator.Feature f)
          Deprecated. Use enable(JsonGenerator.Feature) instead
 void enableParserFeature(JsonParser.Feature f)
          Deprecated. Use enable(JsonParser.Feature) instead
 ObjectCodec getCodec()
           
 boolean isEnabled(JsonGenerator.Feature f)
          Check whether specified generator feature is enabled.
 boolean isEnabled(JsonParser.Feature f)
          Checked whether specified parser feature is enabled.
 boolean isGeneratorFeatureEnabled(JsonGenerator.Feature f)
          Deprecated. Use isEnabled(JsonGenerator.Feature) instead
 boolean isParserFeatureEnabled(JsonParser.Feature f)
          Deprecated. Use isEnabled(JsonParser.Feature) instead
 JsonFactory setCodec(ObjectCodec oc)
           
 void setGeneratorFeature(JsonGenerator.Feature f, boolean state)
          Deprecated. Use configure(JsonGenerator.Feature, boolean) instead
 void setParserFeature(JsonParser.Feature f, boolean state)
          Deprecated. Use configure(JsonParser.Feature, boolean) instead
 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

_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.


_parserFeatures

protected int _parserFeatures

_generatorFeatures

protected int _generatorFeatures
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

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

Since:
1.2

enable

public JsonFactory enable(JsonParser.Feature f)
Method for enabling specified parser feature (check JsonParser.Feature for list of features)

Since:
1.2

disable

public JsonFactory disable(JsonParser.Feature f)
Method for disabling specified parser features (check JsonParser.Feature for list of features)

Since:
1.2

isEnabled

public final boolean isEnabled(JsonParser.Feature f)
Checked whether specified parser feature is enabled.

Since:
1.2

enableParserFeature

public final void enableParserFeature(JsonParser.Feature f)
Deprecated. Use enable(JsonParser.Feature) instead


disableParserFeature

public final void disableParserFeature(JsonParser.Feature f)
Deprecated. Use disable(JsonParser.Feature) instead


setParserFeature

public final void setParserFeature(JsonParser.Feature f,
                                   boolean state)
Deprecated. Use configure(JsonParser.Feature, boolean) instead


isParserFeatureEnabled

public final boolean isParserFeatureEnabled(JsonParser.Feature f)
Deprecated. Use isEnabled(JsonParser.Feature) instead


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)

Since:
1.2

enable

public JsonFactory enable(JsonGenerator.Feature f)
Method for enabling specified generator features (check JsonGenerator.Feature for list of features)

Since:
1.2

disable

public JsonFactory disable(JsonGenerator.Feature f)
Method for disabling specified generator feature (check JsonGenerator.Feature for list of features)

Since:
1.2

isEnabled

public final boolean isEnabled(JsonGenerator.Feature f)
Check whether specified generator feature is enabled.

Since:
1.2

enableGeneratorFeature

@Deprecated
public final void enableGeneratorFeature(JsonGenerator.Feature f)
Deprecated. Use enable(JsonGenerator.Feature) instead


disableGeneratorFeature

@Deprecated
public final void disableGeneratorFeature(JsonGenerator.Feature f)
Deprecated. Use disable(JsonGenerator.Feature) instead


setGeneratorFeature

@Deprecated
public final void setGeneratorFeature(JsonGenerator.Feature f,
                                                 boolean state)
Deprecated. Use configure(JsonGenerator.Feature, boolean) instead


isGeneratorFeatureEnabled

@Deprecated
public final boolean isGeneratorFeatureEnabled(JsonGenerator.Feature f)
Deprecated. Use isEnabled(JsonGenerator.Feature) instead


setCodec

public JsonFactory setCodec(ObjectCodec oc)

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 json parser instance to parse 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
Throws:
IOException
JsonParseException

createJsonParser

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

createJsonParser

public JsonParser createJsonParser(String content)
                            throws IOException,
                                   JsonParseException
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.

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(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

_createContext

protected IOContext _createContext(Object srcRef,
                                   boolean resourceManaged)
Overridable factory method that actually instantiates desired context object.


_createJsonParser

protected JsonParser _createJsonParser(InputStream in,
                                       IOContext ctxt)
                                throws IOException,
                                       JsonParseException
Overridable factory method that actually instantiates desired parser.

Throws:
IOException
JsonParseException

_createJsonParser

protected JsonParser _createJsonParser(Reader r,
                                       IOContext ctxt)
                                throws IOException,
                                       JsonParseException
Overridable factory method that actually instantiates desired parser.

Throws:
IOException
JsonParseException

_createJsonParser

protected JsonParser _createJsonParser(byte[] data,
                                       int offset,
                                       int len,
                                       IOContext ctxt)
                                throws IOException,
                                       JsonParseException
Overridable factory method that actually instantiates desired parser.

Throws:
IOException
JsonParseException

_createJsonGenerator

protected JsonGenerator _createJsonGenerator(Writer out,
                                             IOContext ctxt)
                                      throws IOException
Overridable factory method that actually instantiates desired generator.

Throws:
IOException

_createUTF8JsonGenerator

protected JsonGenerator _createUTF8JsonGenerator(OutputStream out,
                                                 IOContext ctxt)
                                          throws IOException
Overridable factory method that actually instantiates desired generator that is specifically to output content using specified output stream and using UTF-8 encoding.

Throws:
IOException

_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


_createWriter

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

_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