org.apache.lucene.analysis.core

Class StopFilter

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.TokenFilter

org.apache.lucene.analysis.util.FilteringTokenFilter

org.apache.lucene.analysis.core.StopFilter

All Implemented Interfaces:

Closeable, AutoCloseable

public final class StopFilter
extends FilteringTokenFilter

Removes stop words from a token stream.

You may specify the Version compatibility when creating StopFilter:

• As of 3.1, StopFilter correctly handles Unicode 4.0 supplementary characters in stopwords and position increments are preserved

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

AttributeSource.State

Field Summary

Fields inherited from class org.apache.lucene.analysis.util.FilteringTokenFilter

version

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

input

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

DEFAULT_TOKEN_ATTRIBUTE_FACTORY

Fields inherited from class org.apache.lucene.util.AttributeSource

DEFAULT_ATTRIBUTE_FACTORY

Constructor Summary

Constructors

Constructor and Description
StopFilter(TokenStream in, CharArraySet stopWords) Constructs a filter which removes words from the input TokenStream that are named in the Set.
StopFilter(Version matchVersion, TokenStream in, CharArraySet stopWords) Deprecated. Use StopFilter(TokenStream, CharArraySet)

Method Summary

Methods

Modifier and Type	Method and Description
protected boolean	accept() Returns the next input Token whose term() is not a stop word.
static CharArraySet	makeStopSet(List<?> stopWords) Builds a Set from an array of stop words, appropriate for passing into the StopFilter constructor.
static CharArraySet	makeStopSet(List<?> stopWords, boolean ignoreCase) Creates a stopword set from the given stopword list.
static CharArraySet	makeStopSet(String... stopWords) Builds a Set from an array of stop words, appropriate for passing into the StopFilter constructor.
static CharArraySet	makeStopSet(String[] stopWords, boolean ignoreCase) Creates a stopword set from the given stopword array.
static CharArraySet	makeStopSet(Version matchVersion, List<?> stopWords) Deprecated. Use makeStopSet(List)
static CharArraySet	makeStopSet(Version matchVersion, List<?> stopWords, boolean ignoreCase) Deprecated. Use makeStopSet(List,boolean)
static CharArraySet	makeStopSet(Version matchVersion, String... stopWords) Deprecated. Use makeStopSet(String...)
static CharArraySet	makeStopSet(Version matchVersion, String[] stopWords, boolean ignoreCase) Deprecated. Use makeStopSet(String[],boolean)

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

end, getEnablePositionIncrements, incrementToken, reset, setEnablePositionIncrements

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

close

Methods inherited from class org.apache.lucene.util.AttributeSource

addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, restoreState, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

StopFilter

public StopFilter(TokenStream in,
          CharArraySet stopWords)

Constructs a filter which removes words from the input TokenStream that are named in the Set.

Parameters:

in - Input stream

stopWords - A CharArraySet representing the stopwords.

See Also:

makeStopSet(java.lang.String...)

StopFilter

@Deprecated
public StopFilter(Version matchVersion,
                     TokenStream in,
                     CharArraySet stopWords)

Deprecated. Use StopFilter(TokenStream, CharArraySet)

Method Detail

makeStopSet

public static CharArraySet makeStopSet(String... stopWords)

Builds a Set from an array of stop words, appropriate for passing into the StopFilter constructor. This permits this stopWords construction to be cached once when an Analyzer is constructed.

Parameters:

stopWords - An array of stopwords

See Also:

passing false to ignoreCase

makeStopSet

@Deprecated
public static CharArraySet makeStopSet(Version matchVersion,
                                  String... stopWords)

Deprecated. Use makeStopSet(String...)

makeStopSet

public static CharArraySet makeStopSet(List<?> stopWords)

Builds a Set from an array of stop words, appropriate for passing into the StopFilter constructor. This permits this stopWords construction to be cached once when an Analyzer is constructed.

Parameters:

stopWords - A List of Strings or char[] or any other toString()-able list representing the stopwords

Returns:

A Set (CharArraySet) containing the words

See Also:

passing false to ignoreCase

makeStopSet

@Deprecated
public static CharArraySet makeStopSet(Version matchVersion,
                                  List<?> stopWords)

Deprecated. Use makeStopSet(List)

makeStopSet

public static CharArraySet makeStopSet(String[] stopWords,
                       boolean ignoreCase)

Creates a stopword set from the given stopword array.

Parameters:

stopWords - An array of stopwords

ignoreCase - If true, all words are lower cased first.

Returns:

a Set containing the words

makeStopSet

@Deprecated
public static CharArraySet makeStopSet(Version matchVersion,
                                  String[] stopWords,
                                  boolean ignoreCase)

Deprecated. Use makeStopSet(String[],boolean)

makeStopSet

public static CharArraySet makeStopSet(List<?> stopWords,
                       boolean ignoreCase)

Creates a stopword set from the given stopword list.

Parameters:

stopWords - A List of Strings or char[] or any other toString()-able list representing the stopwords

ignoreCase - if true, all words are lower cased first

Returns:

A Set (CharArraySet) containing the words

makeStopSet

@Deprecated
public static CharArraySet makeStopSet(Version matchVersion,
                                  List<?> stopWords,
                                  boolean ignoreCase)

Deprecated. Use makeStopSet(List,boolean)

accept

protected boolean accept()

Returns the next input Token whose term() is not a stop word.

Specified by:

accept in class FilteringTokenFilter