Codec (Lucene 8.9.0 API)乐学网一站式学习平台

java.lang.Object
- org.apache.lucene.codecs.Codec

All Implemented Interfaces:

NamedSPILoader.NamedSPI

Direct Known Subclasses:

FilterCodec, Lucene87Codec
```
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 and Description

protected Codec(String name)
Creates a new codec.

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

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`static Set<String>`	`availableCodecs()` returns a list of all available codec names
`abstract CompoundFormat`	`compoundFormat()` Encodes/decodes compound files
`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 `IndexWriterConfig`s.
`String`	`getName()` Returns this codec's name
`abstract LiveDocsFormat`	`liveDocsFormat()` Encodes/decodes live docs
`abstract NormsFormat`	`normsFormat()` Encodes/decodes document normalization values
`abstract PointsFormat`	`pointsFormat()` Encodes/decodes points index
`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 `IndexWriterConfig`s.
`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
  - compoundFormat
```
public abstract CompoundFormat compoundFormat()
```
    Encodes/decodes compound files
  - pointsFormat
```
public abstract PointsFormat pointsFormat()
```
    Encodes/decodes points index
  - 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

Class Codec

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Codec

Method Detail

getName

postingsFormat

docValuesFormat

storedFieldsFormat

termVectorsFormat

fieldInfosFormat

segmentInfoFormat

normsFormat

liveDocsFormat

compoundFormat

pointsFormat

forName

availableCodecs

reloadCodecs

getDefault

setDefault

toString