org.apache.lucene.analysis.nl
Class DutchAnalyzer

java.lang.Object
  extended by org.apache.lucene.analysis.Analyzer
      extended by org.apache.lucene.analysis.ReusableAnalyzerBase
          extended by org.apache.lucene.analysis.nl.DutchAnalyzer
All Implemented Interfaces:
Closeable

public final class DutchAnalyzer
extends ReusableAnalyzerBase

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 must specify the required Version compatibility when creating DutchAnalyzer:

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


Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.lucene.analysis.ReusableAnalyzerBase
ReusableAnalyzerBase.TokenStreamComponents
 
Field Summary
static String DEFAULT_STOPWORD_FILE
          File containing default Dutch stopwords.
static String[] DUTCH_STOP_WORDS
          Deprecated. use getDefaultStopSet() instead
 
Constructor Summary
DutchAnalyzer(Version matchVersion)
          Builds an analyzer with the default stop words (getDefaultStopSet()) and a few default entries for the stem exclusion table.
DutchAnalyzer(Version matchVersion, File stopwords)
          Deprecated. use DutchAnalyzer(Version, Set) instead
DutchAnalyzer(Version matchVersion, HashSet<?> stopwords)
          Deprecated. use DutchAnalyzer(Version, Set) instead
DutchAnalyzer(Version matchVersion, Set<?> stopwords)
           
DutchAnalyzer(Version matchVersion, Set<?> stopwords, Set<?> stemExclusionTable)
           
DutchAnalyzer(Version matchVersion, String... stopwords)
          Deprecated. use DutchAnalyzer(Version, Set) instead
 
Method Summary
protected  ReusableAnalyzerBase.TokenStreamComponents createComponents(String fieldName, Reader aReader)
          Returns a (possibly reused) TokenStream which tokenizes all the text in the provided Reader.
static Set<?> getDefaultStopSet()
          Returns an unmodifiable instance of the default stop-words set.
 void setStemDictionary(File stemdictFile)
          Reads a stemdictionary file , that overrules the stemming algorithm This is a textfile that contains per line word\tstem, i.e: two tab seperated words
 void setStemExclusionTable(File exclusionlist)
          Deprecated. use DutchAnalyzer(Version, Set, Set) instead
 void setStemExclusionTable(HashSet<?> exclusionlist)
          Deprecated. use DutchAnalyzer(Version, Set, Set) instead
 void setStemExclusionTable(String... exclusionlist)
          Deprecated. use DutchAnalyzer(Version, Set, Set) instead
 
Methods inherited from class org.apache.lucene.analysis.ReusableAnalyzerBase
initReader, reusableTokenStream, tokenStream
 
Methods inherited from class org.apache.lucene.analysis.Analyzer
close, getOffsetGap, getPositionIncrementGap, getPreviousTokenStream, setPreviousTokenStream
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

DUTCH_STOP_WORDS

@Deprecated
public static final String[] DUTCH_STOP_WORDS
Deprecated. use getDefaultStopSet() instead
List of typical Dutch stopwords.


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


DutchAnalyzer

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

DutchAnalyzer

public DutchAnalyzer(Version matchVersion,
                     Set<?> stopwords,
                     Set<?> stemExclusionTable)

DutchAnalyzer

@Deprecated
public DutchAnalyzer(Version matchVersion,
                                String... stopwords)
Deprecated. use DutchAnalyzer(Version, Set) instead

Builds an analyzer with the given stop words.

Parameters:
matchVersion -
stopwords -

DutchAnalyzer

@Deprecated
public DutchAnalyzer(Version matchVersion,
                                HashSet<?> stopwords)
Deprecated. use DutchAnalyzer(Version, Set) instead

Builds an analyzer with the given stop words.

Parameters:
stopwords -

DutchAnalyzer

@Deprecated
public DutchAnalyzer(Version matchVersion,
                                File stopwords)
Deprecated. use DutchAnalyzer(Version, Set) instead

Builds an analyzer with the given stop words.

Parameters:
stopwords -
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.

setStemExclusionTable

@Deprecated
public void setStemExclusionTable(String... exclusionlist)
Deprecated. use DutchAnalyzer(Version, Set, Set) instead

Builds an exclusionlist from an array of Strings.

Parameters:
exclusionlist -

setStemExclusionTable

@Deprecated
public void setStemExclusionTable(HashSet<?> exclusionlist)
Deprecated. use DutchAnalyzer(Version, Set, Set) instead

Builds an exclusionlist from a Hashtable.


setStemExclusionTable

@Deprecated
public void setStemExclusionTable(File exclusionlist)
Deprecated. use DutchAnalyzer(Version, Set, Set) instead

Builds an exclusionlist from the words contained in the given file.


setStemDictionary

public void setStemDictionary(File stemdictFile)
Reads a stemdictionary file , that overrules the stemming algorithm This is a textfile that contains per line word\tstem, i.e: two tab seperated words


createComponents

protected ReusableAnalyzerBase.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 ReusableAnalyzerBase
Parameters:
fieldName - the name of the fields content passed to the ReusableAnalyzerBase.TokenStreamComponents sink as a reader
aReader - the reader passed to the Tokenizer constructor
Returns:
A TokenStream built from a StandardTokenizer filtered with StandardFilter, LowerCaseFilter, StopFilter, KeywordMarkerFilter if a stem exclusion set is provided, StemmerOverrideFilter, and SnowballFilter


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