Module org.apache.lucene.analysis.common

Package org.apache.lucene.analysis.nl

Class DutchAnalyzer

java.lang.Object

org.apache.lucene.analysis.Analyzer

org.apache.lucene.analysis.nl.DutchAnalyzer

All Implemented Interfaces:

Closeable, AutoCloseable

public final class DutchAnalyzer
extends Analyzer

Analyzer for Dutch language.

Supports an external list of stopwords (words that will not be indexed at all), an external list of exclusions (word that will not be stemmed, but indexed) and an external list of word-stem pairs that overrule the algorithm (dictionary stemming). A default set of stopwords is used unless an alternative list is specified, but the exclusion list is empty by default.

Since:

3.1

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	DutchAnalyzer.DefaultSetHolder

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 String	DEFAULT_STOPWORD_FILE	File containing default Dutch stopwords.
private final CharArraySet	excltable	Contains words that should be indexed but not stemmed.
private final StemmerOverrideFilter.StemmerOverrideMap	stemdict
private final CharArraySet	stoptable	Contains the stopwords used with the StopFilter.

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

GLOBAL_REUSE_STRATEGY, PER_FIELD_REUSE_STRATEGY

Constructor Summary

Constructors

Constructor	Description
DutchAnalyzer()	Builds an analyzer with the default stop words (getDefaultStopSet()) and a few default entries for the stem exclusion table.
DutchAnalyzer(CharArraySet stopwords)
DutchAnalyzer(CharArraySet stopwords, CharArraySet stemExclusionTable)
DutchAnalyzer(CharArraySet stopwords, CharArraySet stemExclusionTable, CharArrayMap<String> stemOverrideDict)

Method Summary

Modifier and Type	Method	Description
protected Analyzer.TokenStreamComponents	createComponents(String fieldName)	Returns a (possibly reused) TokenStream 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.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

DEFAULT_STOPWORD_FILE

public static final String DEFAULT_STOPWORD_FILE

File containing default Dutch stopwords.

See Also:

• Constant Field Values

stoptable

private final CharArraySet stoptable

Contains the stopwords used with the StopFilter.

excltable

private final CharArraySet excltable

Contains words that should be indexed but not stemmed.

stemdict

private final StemmerOverrideFilter.StemmerOverrideMap stemdict

Constructor Details

DutchAnalyzer

public DutchAnalyzer()

Builds an analyzer with the default stop words (getDefaultStopSet()) and a few default entries for the stem exclusion table.

DutchAnalyzer

public DutchAnalyzer(CharArraySet stopwords)

DutchAnalyzer

public DutchAnalyzer(CharArraySet stopwords,
 CharArraySet stemExclusionTable)

DutchAnalyzer

public DutchAnalyzer(CharArraySet stopwords,
 CharArraySet stemExclusionTable,
 CharArrayMap<String> stemOverrideDict)

Method Details

getDefaultStopSet

public static CharArraySet getDefaultStopSet()

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

Returns:

an unmodifiable instance of the default stop-words set.

createComponents

protected Analyzer.TokenStreamComponents createComponents(String fieldName)

Returns a (possibly reused) TokenStream 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 TokenStream built from a StandardTokenizer filtered with LowerCaseFilter, StopFilter, SetKeywordMarkerFilter if a stem exclusion set is provided, StemmerOverrideFilter, and SnowballFilter

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