org.apache.lucene.analysis.stempel
Class StempelFilter

java.lang.Object
  extended by org.apache.lucene.util.AttributeSource
      extended by org.apache.lucene.analysis.TokenStream
          extended by org.apache.lucene.analysis.TokenFilter
              extended by org.apache.lucene.analysis.stempel.StempelFilter
All Implemented Interfaces:
Closeable

public final class StempelFilter
extends TokenFilter

Transforms the token stream as per the 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!


Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.AttributeFactory, AttributeSource.State
 
Field Summary
static int DEFAULT_MIN_LENGTH
          Minimum length of input words to be processed.
 
Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
 
Constructor Summary
StempelFilter(TokenStream in, StempelStemmer stemmer)
          Create filter using the supplied stemming table.
StempelFilter(TokenStream in, StempelStemmer stemmer, int minLength)
          Create filter using the supplied stemming table.
 
Method Summary
 boolean incrementToken()
          Returns the next input Token, after being stemmed
 
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, reset
 
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
 

Field Detail

DEFAULT_MIN_LENGTH

public static final int DEFAULT_MIN_LENGTH
Minimum length of input words to be processed. Shorter words are returned unchanged.

See Also:
Constant Field Values
Constructor Detail

StempelFilter

public StempelFilter(TokenStream in,
                     StempelStemmer stemmer)
Create filter using the supplied stemming table.

Parameters:
in - input token stream
stemmer - stemmer

StempelFilter

public StempelFilter(TokenStream in,
                     StempelStemmer stemmer,
                     int minLength)
Create filter using the supplied stemming table.

Parameters:
in - input token stream
stemmer - stemmer
minLength - For performance reasons words shorter than minLength characters are not processed, but simply returned.
Method Detail

incrementToken

public boolean incrementToken()
                       throws IOException
Returns the next input Token, after being stemmed

Specified by:
incrementToken in class TokenStream
Returns:
false for end of stream; true otherwise
Throws:
IOException


Copyright © 2000-2011 Apache Software Foundation. All Rights Reserved.