org.apache.lucene.analysis.stempel
Class StempelFilter

java.lang.Object
  org.apache.lucene.util.AttributeSource
      org.apache.lucene.analysis.TokenStream
          org.apache.lucene.analysis.TokenFilter
              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