org.apache.lucene.analysis.custom

Class CustomAnalyzer

java.lang.Object

org.apache.lucene.analysis.Analyzer

org.apache.lucene.analysis.custom.CustomAnalyzer

All Implemented Interfaces:

Closeable, AutoCloseable

public final class CustomAnalyzer
extends Analyzer

A general-purpose Analyzer that can be created with a builder-style API. Under the hood it uses the factory classes TokenizerFactory, TokenFilterFactory, and CharFilterFactory.

You can create an instance of this Analyzer using the builder by passing the SPI names (as defined by ServiceLoader interface) to it:

 Analyzer ana = CustomAnalyzer.builder(Paths.get("/path/to/config/dir"))
   .withTokenizer(StandardTokenizerFactory.NAME)
   .addTokenFilter(LowerCaseFilterFactory.NAME)
   .addTokenFilter(StopFilterFactory.NAME, "ignoreCase", "false", "words", "stopwords.txt", "format", "wordset")
   .build();
 

The parameters passed to components are also used by Apache Solr and are documented on their corresponding factory classes. Refer to documentation of subclasses of TokenizerFactory, TokenFilterFactory, and CharFilterFactory.

This is the same as the above:

 Analyzer ana = CustomAnalyzer.builder(Paths.get("/path/to/config/dir"))
   .withTokenizer("standard")
   .addTokenFilter("lowercase")
   .addTokenFilter("stop", "ignoreCase", "false", "words", "stopwords.txt", "format", "wordset")
   .build();
 

The list of names to be used for components can be looked up through: TokenizerFactory.availableTokenizers(), TokenFilterFactory.availableTokenFilters(), and CharFilterFactory.availableCharFilters().

You can create conditional branches in the analyzer by using CustomAnalyzer.Builder.when(String, String...) and CustomAnalyzer.Builder.whenTerm(Predicate):

 Analyzer ana = CustomAnalyzer.builder()
    .withTokenizer("standard")
    .addTokenFilter("lowercase")
    .whenTerm(t -> t.length() > 10)
      .addTokenFilter("reversestring")
    .endwhen()
    .build();
 

Since:

5.0.0

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CustomAnalyzer.Builder Builder for CustomAnalyzer.
static class	CustomAnalyzer.ConditionBuilder Factory class for a ConditionalTokenFilter

Nested classes/interfaces inherited from class org.apache.lucene.analysis.Analyzer

Analyzer.ReuseStrategy, Analyzer.TokenStreamComponents

Field Summary

Fields inherited from class org.apache.lucene.analysis.Analyzer

GLOBAL_REUSE_STRATEGY, PER_FIELD_REUSE_STRATEGY

Method Summary

Modifier and Type	Method and Description
static CustomAnalyzer.Builder	builder() Returns a builder for custom analyzers that loads all resources from Lucene's classloader.
static CustomAnalyzer.Builder	builder(Path configDir) Returns a builder for custom analyzers that loads all resources from the given file system base directory.
static CustomAnalyzer.Builder	builder(ResourceLoader loader) Returns a builder for custom analyzers that loads all resources using the given ResourceLoader.
protected Analyzer.TokenStreamComponents	createComponents(String fieldName)
List<CharFilterFactory>	getCharFilterFactories() Returns the list of char filters that are used in this analyzer.
int	getOffsetGap(String fieldName)
int	getPositionIncrementGap(String fieldName)
List<TokenFilterFactory>	getTokenFilterFactories() Returns the list of token filters that are used in this analyzer.
TokenizerFactory	getTokenizerFactory() Returns the tokenizer that is used in this analyzer.
protected Reader	initReader(String fieldName, Reader reader)
protected Reader	initReaderForNormalization(String fieldName, Reader reader)
protected TokenStream	normalize(String fieldName, TokenStream in)
String	toString()

Methods inherited from class org.apache.lucene.analysis.Analyzer

attributeFactory, close, getReuseStrategy, getVersion, normalize, setVersion, tokenStream, tokenStream

Methods inherited from class java.lang.Object

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

Method Detail

builder

public static CustomAnalyzer.Builder builder()

Returns a builder for custom analyzers that loads all resources from Lucene's classloader. All path names given must be absolute with package prefixes.

builder

public static CustomAnalyzer.Builder builder(Path configDir)

Returns a builder for custom analyzers that loads all resources from the given file system base directory. Place, e.g., stop word files there. Files that are not in the given directory are loaded from Lucene's classloader.

builder

public static CustomAnalyzer.Builder builder(ResourceLoader loader)

Returns a builder for custom analyzers that loads all resources using the given ResourceLoader.

initReader

protected Reader initReader(String fieldName,
                            Reader reader)

Overrides:

initReader in class Analyzer

initReaderForNormalization

protected Reader initReaderForNormalization(String fieldName,
                                            Reader reader)

Overrides:

initReaderForNormalization in class Analyzer

createComponents

protected Analyzer.TokenStreamComponents createComponents(String fieldName)

Specified by:

createComponents in class Analyzer

normalize

protected TokenStream normalize(String fieldName,
                                TokenStream in)

Overrides:

normalize in class Analyzer

getPositionIncrementGap

public int getPositionIncrementGap(String fieldName)

Overrides:

getPositionIncrementGap in class Analyzer

getOffsetGap

public int getOffsetGap(String fieldName)

Overrides:

getOffsetGap in class Analyzer

getCharFilterFactories

public List<CharFilterFactory> getCharFilterFactories()

Returns the list of char filters that are used in this analyzer.

getTokenizerFactory

public TokenizerFactory getTokenizerFactory()

Returns the tokenizer that is used in this analyzer.

getTokenFilterFactories

public List<TokenFilterFactory> getTokenFilterFactories()

Returns the list of token filters that are used in this analyzer.

toString

public String toString()

Overrides:

toString in class Object