Module org.apache.lucene.analysis.common

Package org.apache.lucene.analysis.en

Class EnglishAnalyzer

java.lang.Object

org.apache.lucene.analysis.Analyzer

org.apache.lucene.analysis.StopwordAnalyzerBase

org.apache.lucene.analysis.en.EnglishAnalyzer

All Implemented Interfaces:

Closeable, AutoCloseable

public final class EnglishAnalyzer
extends StopwordAnalyzerBase

Analyzer for English.

Since:

3.1

Nested Class Summary

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

Analyzer.ReuseStrategy, Analyzer.TokenStreamComponents

Field Summary

Fields

Modifier and Type	Field	Description
static final CharArraySet	ENGLISH_STOP_WORDS_SET	An unmodifiable set containing some common English words that are not usually useful for searching.
private final CharArraySet	stemExclusionSet

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

stopwords

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

GLOBAL_REUSE_STRATEGY, PER_FIELD_REUSE_STRATEGY

Constructor Summary

Constructors

Constructor	Description
EnglishAnalyzer()	Builds an analyzer with the default stop words: getDefaultStopSet().
EnglishAnalyzer(CharArraySet stopwords)	Builds an analyzer with the given stop words.
EnglishAnalyzer(CharArraySet stopwords, CharArraySet stemExclusionSet)	Builds an analyzer with the given stop words.

Method Summary

Modifier and Type	Method	Description
protected Analyzer.TokenStreamComponents	createComponents(String fieldName)	Creates a Analyzer.TokenStreamComponents which tokenizes all the text in the provided Reader.
static CharArraySet	getDefaultStopSet()	Returns an unmodifiable instance of the default stop words set.
protected TokenStream	normalize(String fieldName, TokenStream in)	Wrap the given TokenStream in order to apply normalization filters.

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

getStopwordSet, loadStopwordSet, loadStopwordSet, loadStopwordSet

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

attributeFactory, close, getOffsetGap, getPositionIncrementGap, getReuseStrategy, initReader, initReaderForNormalization, normalize, tokenStream, tokenStream

Methods inherited from class java.lang.Object

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

Field Details

ENGLISH_STOP_WORDS_SET

public static final CharArraySet ENGLISH_STOP_WORDS_SET

An unmodifiable set containing some common English words that are not usually useful for searching.

stemExclusionSet

private final CharArraySet stemExclusionSet

Constructor Details

EnglishAnalyzer

public EnglishAnalyzer()

Builds an analyzer with the default stop words: getDefaultStopSet().

EnglishAnalyzer

public EnglishAnalyzer(CharArraySet stopwords)

Builds an analyzer with the given stop words.

Parameters:

stopwords - a stopword set

EnglishAnalyzer

public EnglishAnalyzer(CharArraySet stopwords,
 CharArraySet stemExclusionSet)

Builds an analyzer with the given stop words. If a non-empty stem exclusion set is provided this analyzer will add a SetKeywordMarkerFilter before stemming.

Parameters:

stopwords - a stopword set

stemExclusionSet - a set of terms not to be stemmed

Method Details

getDefaultStopSet

public static CharArraySet getDefaultStopSet()

Returns an unmodifiable instance of the default stop words set.

Returns:

default stop words set.

createComponents

protected Analyzer.TokenStreamComponents createComponents(String fieldName)

Creates a Analyzer.TokenStreamComponents which tokenizes all the text in the provided Reader.

Specified by:

createComponents in class Analyzer

Parameters:

fieldName - the name of the fields content passed to the Analyzer.TokenStreamComponents sink as a reader

Returns:

A Analyzer.TokenStreamComponents built from an StandardTokenizer filtered with EnglishPossessiveFilter, LowerCaseFilter, StopFilter, SetKeywordMarkerFilter if a stem exclusion set is provided and PorterStemFilter.

normalize

protected TokenStream normalize(String fieldName,
 TokenStream in)

Description copied from class: Analyzer

Wrap the given TokenStream in order to apply normalization filters. The default implementation returns the TokenStream as-is. This is used by Analyzer.normalize(String, String).

Overrides:

normalize in class Analyzer