Package org.apache.lucene.analysis.de

Class GermanAnalyzer

java.lang.Object

org.apache.lucene.analysis.Analyzer

org.apache.lucene.analysis.util.StopwordAnalyzerBase

org.apache.lucene.analysis.de.GermanAnalyzer

All Implemented Interfaces:

Closeable, AutoCloseable

public final class GermanAnalyzer
extends StopwordAnalyzerBase

Analyzer for German language.

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

You must specify the required Version compatibility when creating GermanAnalyzer:

• As of 3.6, GermanLightStemFilter is used for less aggressive stemming.
• As of 3.1, Snowball stemming is done with SnowballFilter, and Snowball stopwords are used by default.
• As of 2.9, StopFilter preserves position increments

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	Description
static final String	DEFAULT_STOPWORD_FILE	File containing default German stopwords.

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

GLOBAL_REUSE_STRATEGY, PER_FIELD_REUSE_STRATEGY

Constructor Summary

Constructors

Constructor	Description
GermanAnalyzer(Version matchVersion)	Builds an analyzer with the default stop words: getDefaultStopSet().
GermanAnalyzer(Version matchVersion, CharArraySet stopwords)	Builds an analyzer with the given stop words
GermanAnalyzer(Version matchVersion, CharArraySet stopwords, CharArraySet stemExclusionSet)	Builds an analyzer with the given stop words

Method Summary

Modifier and Type	Method	Description
static final CharArraySet	getDefaultStopSet()	Returns a set of default German-stopwords

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

getStopwordSet

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

close, getOffsetGap, getPositionIncrementGap, getReuseStrategy, tokenStream, tokenStream

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_STOPWORD_FILE

public static final String DEFAULT_STOPWORD_FILE

File containing default German stopwords.

See Also:

• Constant Field Values

Constructor Details

GermanAnalyzer

public GermanAnalyzer(Version matchVersion)

Builds an analyzer with the default stop words: getDefaultStopSet().

GermanAnalyzer

public GermanAnalyzer(Version matchVersion,
 CharArraySet stopwords)

Builds an analyzer with the given stop words

Parameters:

matchVersion - lucene compatibility version

stopwords - a stopword set

GermanAnalyzer

public GermanAnalyzer(Version matchVersion,
 CharArraySet stopwords,
 CharArraySet stemExclusionSet)

Builds an analyzer with the given stop words

Parameters:

matchVersion - lucene compatibility version

stopwords - a stopword set

stemExclusionSet - a stemming exclusion set

Method Details

getDefaultStopSet

public static final CharArraySet getDefaultStopSet()

Returns a set of default German-stopwords

Returns:

a set of default German-stopwords