org.apache.lucene.analysis.ar
Class ArabicAnalyzer

java.lang.Object
  org.apache.lucene.analysis.Analyzer
      org.apache.lucene.analysis.ar.ArabicAnalyzer

All Implemented Interfaces:

Closeable

public final class ArabicAnalyzer
extends Analyzer

Analyzer for Arabic.

This analyzer implements light-stemming as specified by: Light Stemming for Arabic Information Retrieval http://www.mtholyoke.edu/~lballest/Pubs/arab_stem05.pdf

The analysis package contains three primary components:

• ArabicNormalizationFilter: Arabic orthographic normalization.
• ArabicStemFilter: Arabic light stemming
• Arabic stop words file: a set of default Arabic stop words.

Field Summary

static String	DEFAULT_STOPWORD_FILE File containing default Arabic stopwords.
static String	STOPWORDS_COMMENT Deprecated. use WordlistLoader.getWordSet(File, String) directly

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

overridesTokenStreamMethod

Constructor Summary

ArabicAnalyzer(Version matchVersion)
Builds an analyzer with the default stop words: DEFAULT_STOPWORD_FILE.

ArabicAnalyzer(Version matchVersion, File stopwords)
Deprecated. use ArabicAnalyzer(Version, Set) instead

ArabicAnalyzer(Version matchVersion, Hashtable<?,?> stopwords)
Deprecated. use ArabicAnalyzer(Version, Set) instead

ArabicAnalyzer(Version matchVersion, Set<?> stopwords)
Builds an analyzer with the given stop words

ArabicAnalyzer(Version matchVersion, String... stopwords)
Deprecated. use ArabicAnalyzer(Version, Set) instead

Method Summary

static Set<String>	getDefaultStopSet() Returns an unmodifiable instance of the default stop-words set.
TokenStream	reusableTokenStream(String fieldName, Reader reader) Returns a (possibly reused) TokenStream which tokenizes all the text in the provided Reader.
TokenStream	tokenStream(String fieldName, Reader reader) Creates a TokenStream which tokenizes all the text in the provided Reader.

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

close, getOffsetGap, getPositionIncrementGap, getPreviousTokenStream, setOverridesTokenStreamMethod, setPreviousTokenStream

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_STOPWORD_FILE

public static final String DEFAULT_STOPWORD_FILE

File containing default Arabic stopwords. Default stopword list is from http://members.unine.ch/jacques.savoy/clef/index.html The stopword list is BSD-Licensed.

See Also:

Constant Field Values

STOPWORDS_COMMENT

public static final String STOPWORDS_COMMENT

Deprecated. use WordlistLoader.getWordSet(File, String) directly

The comment character in the stopwords file. All lines prefixed with this will be ignored

See Also:

Constant Field Values

Constructor Detail

ArabicAnalyzer

public ArabicAnalyzer(Version matchVersion)

Builds an analyzer with the default stop words: DEFAULT_STOPWORD_FILE.

ArabicAnalyzer

public ArabicAnalyzer(Version matchVersion,
                      Set<?> stopwords)

Builds an analyzer with the given stop words

Parameters:

matchVersion - lucene compatibility version

stopwords - a stopword set

ArabicAnalyzer

public ArabicAnalyzer(Version matchVersion,
                      String... stopwords)

Deprecated. use ArabicAnalyzer(Version, Set) instead

Builds an analyzer with the given stop words.

ArabicAnalyzer

public ArabicAnalyzer(Version matchVersion,
                      Hashtable<?,?> stopwords)

Deprecated. use ArabicAnalyzer(Version, Set) instead

Builds an analyzer with the given stop words.

ArabicAnalyzer

public ArabicAnalyzer(Version matchVersion,
                      File stopwords)
               throws IOException

Deprecated. use ArabicAnalyzer(Version, Set) instead

Builds an analyzer with the given stop words. Lines can be commented out using STOPWORDS_COMMENT

Throws:

IOException

Method Detail

getDefaultStopSet

public static Set<String> getDefaultStopSet()

Returns an unmodifiable instance of the default stop-words set.

Returns:

an unmodifiable instance of the default stop-words set.

tokenStream

public final TokenStream tokenStream(String fieldName,
                                     Reader reader)

Creates a TokenStream which tokenizes all the text in the provided Reader.

Specified by:

tokenStream in class Analyzer

Returns:

A TokenStream built from an ArabicLetterTokenizer filtered with LowerCaseFilter, StopFilter, ArabicNormalizationFilter and ArabicStemFilter.

reusableTokenStream

public TokenStream reusableTokenStream(String fieldName,
                                       Reader reader)
                                throws IOException

Returns a (possibly reused) TokenStream which tokenizes all the text in the provided Reader.

Overrides:

reusableTokenStream in class Analyzer

Returns:

A TokenStream built from an ArabicLetterTokenizer filtered with LowerCaseFilter, StopFilter, ArabicNormalizationFilter and ArabicStemFilter.

Throws:

IOException