Package org.apache.lucene.codecs

Class Codec

java.lang.Object

org.apache.lucene.codecs.Codec

All Implemented Interfaces:

NamedSPILoader.NamedSPI

Direct Known Subclasses:

FilterCodec, Lucene3xCodec, Lucene40Codec, Lucene41Codec, Lucene42Codec, Lucene45Codec, Lucene46Codec

public abstract class Codec
extends Object
implements NamedSPILoader.NamedSPI

Encodes/decodes an inverted index segment.

Note, when extending this class, the name (getName()) is written into the index. In order for the segment to be read, the name must resolve to your implementation via forName(String). This method uses Java's Service Provider Interface (SPI) to resolve codec names.

If you implement your own codec, make sure that it has a no-arg constructor so SPI can load it.

See Also:

ServiceLoader

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Codec(String name)	Creates a new codec.

Method Summary

Modifier and Type	Method	Description
static Set<String>	availableCodecs()	returns a list of all available codec names
abstract DocValuesFormat	docValuesFormat()	Encodes/decodes docvalues
abstract FieldInfosFormat	fieldInfosFormat()	Encodes/decodes field infos file
static Codec	forName(String name)	looks up a codec by name
static Codec	getDefault()	expert: returns the default codec used for newly created IndexWriterConfigs.
String	getName()	Returns this codec's name
abstract LiveDocsFormat	liveDocsFormat()	Encodes/decodes live docs
abstract NormsFormat	normsFormat()	Encodes/decodes document normalization values
abstract PostingsFormat	postingsFormat()	Encodes/decodes postings
static void	reloadCodecs(ClassLoader classloader)	Reloads the codec list from the given ClassLoader.
abstract SegmentInfoFormat	segmentInfoFormat()	Encodes/decodes segment info file
static void	setDefault(Codec codec)	expert: sets the default codec used for newly created IndexWriterConfigs.
abstract StoredFieldsFormat	storedFieldsFormat()	Encodes/decodes stored fields
abstract TermVectorsFormat	termVectorsFormat()	Encodes/decodes term vectors
String	toString()	returns the codec's name.

Methods inherited from class java.lang.Object

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

Constructor Detail

Codec

protected Codec(String name)

Creates a new codec.

The provided name will be written into the index segment: in order to for the segment to be read this class should be registered with Java's SPI mechanism (registered in META-INF/ of your jar file, etc).

Parameters:

name - must be all ascii alphanumeric, and less than 128 characters in length.

Method Detail

getName

public final String getName()

Returns this codec's name

Specified by:

getName in interface NamedSPILoader.NamedSPI

postingsFormat

public abstract PostingsFormat postingsFormat()

Encodes/decodes postings

docValuesFormat

public abstract DocValuesFormat docValuesFormat()

Encodes/decodes docvalues

storedFieldsFormat

public abstract StoredFieldsFormat storedFieldsFormat()

Encodes/decodes stored fields

termVectorsFormat

public abstract TermVectorsFormat termVectorsFormat()

Encodes/decodes term vectors

fieldInfosFormat

public abstract FieldInfosFormat fieldInfosFormat()

Encodes/decodes field infos file

segmentInfoFormat

public abstract SegmentInfoFormat segmentInfoFormat()

Encodes/decodes segment info file

normsFormat

public abstract NormsFormat normsFormat()

Encodes/decodes document normalization values

liveDocsFormat

public abstract LiveDocsFormat liveDocsFormat()

Encodes/decodes live docs

forName

public static Codec forName(String name)

looks up a codec by name

availableCodecs

public static Set<String> availableCodecs()

returns a list of all available codec names

reloadCodecs

public static void reloadCodecs(ClassLoader classloader)

Reloads the codec list from the given ClassLoader. Changes to the codecs are visible after the method ends, all iterators (availableCodecs(),...) stay consistent.

NOTE: Only new codecs are added, existing ones are never removed or replaced.

This method is expensive and should only be called for discovery of new codecs on the given classpath/classloader!

getDefault

public static Codec getDefault()

expert: returns the default codec used for newly created IndexWriterConfigs.

setDefault

public static void setDefault(Codec codec)

expert: sets the default codec used for newly created IndexWriterConfigs.

toString

public String toString()

returns the codec's name. Subclasses can override to provide more detail (such as parameters).

Overrides:

toString in class Object