org.apache.lucene.analysis.standard

Class StandardAnalyzer

java.lang.Object

org.apache.lucene.analysis.Analyzer

org.apache.lucene.analysis.util.StopwordAnalyzerBase

org.apache.lucene.analysis.standard.StandardAnalyzer

All Implemented Interfaces:

Closeable

public final class StandardAnalyzer
extends StopwordAnalyzerBase

Filters StandardTokenizer with StandardFilter, LowerCaseFilter and StopFilter, using a list of English stop words.

You must specify the required Version compatibility when creating StandardAnalyzer:

• As of 3.4, Hiragana and Han characters are no longer wrongly split from their combining characters. If you use a previous version number, you get the exact broken behavior for backwards compatibility.
• As of 3.1, StandardTokenizer implements Unicode text segmentation, and StopFilter correctly handles Unicode 4.0 supplementary characters in stopwords. ClassicTokenizer and ClassicAnalyzer are the pre-3.1 implementations of StandardTokenizer and StandardAnalyzer.
• As of 2.9, StopFilter preserves position increments
• As of 2.4, Tokens incorrectly identified as acronyms are corrected (see LUCENE-1068)

Nested Class Summary

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

Analyzer.GlobalReuseStrategy, Analyzer.PerFieldReuseStrategy, Analyzer.ReuseStrategy, Analyzer.TokenStreamComponents

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_MAX_TOKEN_LENGTH Default maximum allowed token length
static CharArraySet	STOP_WORDS_SET An unmodifiable set containing some common English words that are usually not useful for searching.

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

matchVersion, stopwords

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

GLOBAL_REUSE_STRATEGY, PER_FIELD_REUSE_STRATEGY

Constructor Summary

Constructors

Constructor and Description
StandardAnalyzer(Version matchVersion) Builds an analyzer with the default stop words (STOP_WORDS_SET).
StandardAnalyzer(Version matchVersion, CharArraySet stopWords) Builds an analyzer with the given stop words.
StandardAnalyzer(Version matchVersion, Reader stopwords) Builds an analyzer with the stop words from the given reader.

Method Summary

Methods

Modifier and Type	Method and Description
protected Analyzer.TokenStreamComponents	createComponents(String fieldName, Reader reader)
int	getMaxTokenLength()
void	setMaxTokenLength(int length) Set maximum allowed token length.

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

getStopwordSet, loadStopwordSet, loadStopwordSet, loadStopwordSet

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

close, getOffsetGap, getPositionIncrementGap, getReuseStrategy, initReader, tokenStream, tokenStream

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MAX_TOKEN_LENGTH

public static final int DEFAULT_MAX_TOKEN_LENGTH

Default maximum allowed token length

See Also:

Constant Field Values

STOP_WORDS_SET

public static final CharArraySet STOP_WORDS_SET

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

Constructor Detail

StandardAnalyzer

public StandardAnalyzer(Version matchVersion,
                CharArraySet stopWords)

Builds an analyzer with the given stop words.

Parameters:

matchVersion - Lucene version to match See above

stopWords - stop words

StandardAnalyzer

public StandardAnalyzer(Version matchVersion)

Builds an analyzer with the default stop words (STOP_WORDS_SET).

Parameters:

matchVersion - Lucene version to match See above

StandardAnalyzer

public StandardAnalyzer(Version matchVersion,
                Reader stopwords)
                 throws IOException

Builds an analyzer with the stop words from the given reader.

Parameters:

matchVersion - Lucene version to match See above

stopwords - Reader to read stop words from

Throws:

IOException

See Also:

WordlistLoader.getWordSet(Reader, Version)

Method Detail

setMaxTokenLength

public void setMaxTokenLength(int length)

Set maximum allowed token length. If a token is seen that exceeds this length then it is discarded. This setting only takes effect the next time tokenStream or tokenStream is called.

getMaxTokenLength

public int getMaxTokenLength()

See Also:

setMaxTokenLength(int)

createComponents

protected Analyzer.TokenStreamComponents createComponents(String fieldName,
                                              Reader reader)

Specified by:

createComponents in class Analyzer