org.apache.lucene.analysis.fa
Class PersianAnalyzer

java.lang.Object
  org.apache.lucene.analysis.Analyzer
      org.apache.lucene.analysis.fa.PersianAnalyzer

All Implemented Interfaces:

Closeable

public final class PersianAnalyzer
extends Analyzer

Analyzer for Persian.

This Analyzer uses ArabicLetterTokenizer which implies tokenizing around zero-width non-joiner in addition to whitespace. Some persian-specific variant forms (such as farsi yeh and keheh) are standardized. "Stemming" is accomplished via stopwords.

Field Summary

static String	DEFAULT_STOPWORD_FILE File containing default Persian stopwords.
static String	STOPWORDS_COMMENT The comment character in the stopwords file.

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

overridesTokenStreamMethod

Constructor Summary

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

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

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

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

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

Method Summary

static Set<?>	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 Persian 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

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

See Also:

Constant Field Values

Constructor Detail

PersianAnalyzer

public PersianAnalyzer(Version matchVersion)

Builds an analyzer with the default stop words: DEFAULT_STOPWORD_FILE.

PersianAnalyzer

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

Builds an analyzer with the given stop words

Parameters:

matchVersion - lucene compatibility version

stopwords - a stopword set

PersianAnalyzer

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

Deprecated. use PersianAnalyzer(Version, Set) instead

Builds an analyzer with the given stop words.

PersianAnalyzer

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

Deprecated. use PersianAnalyzer(Version, Set) instead

Builds an analyzer with the given stop words.

PersianAnalyzer

public PersianAnalyzer(Version matchVersion,
                       File stopwords)
                throws IOException

Deprecated. use PersianAnalyzer(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<?> getDefaultStopSet()

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

Returns:

an unmodifiable instance of the default stop-words set.

tokenStream

public 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 a ArabicLetterTokenizer filtered with LowerCaseFilter, ArabicNormalizationFilter, PersianNormalizationFilter and Persian Stop words

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 a ArabicLetterTokenizer filtered with LowerCaseFilter, ArabicNormalizationFilter, PersianNormalizationFilter and Persian Stop words

Throws:

IOException