org.apache.lucene.analysis
Class PorterStemFilter

java.lang.Object
  |
  +--org.apache.lucene.analysis.TokenStream
        |
        +--org.apache.lucene.analysis.TokenFilter
              |
              +--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));
}
}

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 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 IOException

Returns the next input Token, after being stemmed

Overrides:

next in class TokenStream