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.

You may specify the Version compatibility when creating DutchAnalyzer:

• As of 3.6, DutchAnalyzer(Version, CharArraySet) and DutchAnalyzer(Version, CharArraySet, CharArraySet) also populate the default entries for the stem override dictionary
• As of 3.1, Snowball stemming is done with SnowballFilter, LowerCaseFilter is used prior to StopFilter, and Snowball stopwords are used by default.

NOTE: This class uses the same Version dependent settings as StandardAnalyzer.

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 String	DEFAULT_STOPWORD_FILE File containing default Dutch stopwords.

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

GLOBAL_REUSE_STRATEGY, PER_FIELD_REUSE_STRATEGY

Constructor Summary

Constructors

Constructor and 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)
DutchAnalyzer(Version matchVersion) Deprecated. Use DutchAnalyzer()
DutchAnalyzer(Version matchVersion, CharArraySet stopwords) Deprecated. Use DutchAnalyzer(CharArraySet)
DutchAnalyzer(Version matchVersion, CharArraySet stopwords, CharArraySet stemExclusionTable) Deprecated. Use DutchAnalyzer(CharArraySet,CharArraySet)
DutchAnalyzer(Version matchVersion, CharArraySet stopwords, CharArraySet stemExclusionTable, CharArrayMap<String> stemOverrideDict) Deprecated. Use DutchAnalyzer(CharArraySet,CharArraySet,CharArrayMap)

Method Summary

Methods

Modifier and Type	Method and Description
protected Analyzer.TokenStreamComponents	createComponents(String fieldName, Reader aReader) 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.

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

close, getOffsetGap, getPositionIncrementGap, getReuseStrategy, getVersion, initReader, setVersion, tokenStream, tokenStream

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 Dutch stopwords.

See Also:

Constant Field Values

Constructor Detail

DutchAnalyzer

public DutchAnalyzer()

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

DutchAnalyzer

@Deprecated
public DutchAnalyzer(Version matchVersion)

Deprecated. Use DutchAnalyzer()

DutchAnalyzer

public DutchAnalyzer(CharArraySet stopwords)

DutchAnalyzer

@Deprecated
public DutchAnalyzer(Version matchVersion,
                        CharArraySet stopwords)

Deprecated. Use DutchAnalyzer(CharArraySet)

DutchAnalyzer

public DutchAnalyzer(CharArraySet stopwords,
             CharArraySet stemExclusionTable)

DutchAnalyzer

@Deprecated
public DutchAnalyzer(Version matchVersion,
                        CharArraySet stopwords,
                        CharArraySet stemExclusionTable)

Deprecated. Use DutchAnalyzer(CharArraySet,CharArraySet)

DutchAnalyzer

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

DutchAnalyzer

@Deprecated
public DutchAnalyzer(Version matchVersion,
                        CharArraySet stopwords,
                        CharArraySet stemExclusionTable,
                        CharArrayMap<String> stemOverrideDict)

Deprecated. Use DutchAnalyzer(CharArraySet,CharArraySet,CharArrayMap)

Method Detail

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,
                                              Reader aReader)

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

Specified by:

createComponents in class Analyzer

Returns:

A TokenStream built from a StandardTokenizer filtered with StandardFilter, LowerCaseFilter, StopFilter, SetKeywordMarkerFilter if a stem exclusion set is provided, StemmerOverrideFilter, and SnowballFilter