org.apache.lucene.analysis
Class PorterStemFilter

java.lang.Object
  extended by org.apache.lucene.analysis.TokenStream
      extended by org.apache.lucene.analysis.TokenFilter
          extended by org.apache.lucene.analysis.PorterStemFilter

public final class PorterStemFilter
extends TokenFilter

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 {
      public final TokenStream tokenStream(String fieldName, Reader reader) {
        return new PorterStemFilter(new LowerCaseTokenizer(reader));
      }
    }
    


Field Summary
 
Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
 
Constructor Summary
PorterStemFilter(TokenStream in)
           
 
Method Summary
 Token next()
          Returns the next input Token, after being stemmed
 
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close
 
Methods inherited from class org.apache.lucene.analysis.TokenStream
reset
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

PorterStemFilter

public PorterStemFilter(TokenStream in)
Method Detail

next

public final Token next()
                 throws java.io.IOException
Returns the next input Token, after being stemmed

Specified by:
next in class TokenStream
Throws:
java.io.IOException


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