Package org.apache.lucene.analysis.en
Class PorterStemFilter
java.lang.Object
org.apache.lucene.util.AttributeSource
org.apache.lucene.analysis.TokenStream
org.apache.lucene.analysis.TokenFilter
org.apache.lucene.analysis.en.PorterStemFilter
- All Implemented Interfaces:
Closeable
,AutoCloseable
,Unwrappable<TokenStream>
Transforms the token stream as per the Porter stemming algorithm. Note: the input to the stemming
filter must already be in lower case, so you will need to use LowerCaseFilter or
LowerCaseTokenizer farther down the Tokenizer chain in order for this to work properly!
To use this filter with other analyzers, you'll want to write an Analyzer class that sets up
the TokenStream chain as you want it. To use this with LowerCaseTokenizer, for example, you'd
write an analyzer like this:
class MyAnalyzer extends Analyzer { @Override protected TokenStreamComponents createComponents(String fieldName) { Tokenizer source = new LowerCaseTokenizer(version, reader); return new TokenStreamComponents(source, new PorterStemFilter(source)); } }
Note: This filter is aware of the KeywordAttribute
. To prevent certain terms from
being passed to the stemmer KeywordAttribute.isKeyword()
should be set to true
in a previous TokenStream
.
Note: For including the original term as well as the stemmed version, see KeywordRepeatFilterFactory
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
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Field Summary
Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
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Constructor Summary
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Method Summary
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, reset, unwrap
Methods inherited from class org.apache.lucene.util.AttributeSource
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
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Constructor Details
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PorterStemFilter
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Method Details
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incrementToken
- Specified by:
incrementToken
in classTokenStream
- Throws:
IOException
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