org.apache.lucene.analysis.hunspell
Class HunspellStemFilter

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.hunspell.HunspellStemFilter
All Implemented Interfaces:
Closeable

public final class HunspellStemFilter
extends TokenFilter

TokenFilter that uses hunspell affix rules and words to stem tokens. Since hunspell supports a word having multiple stems, this filter can emit multiple tokens for each consumed token


Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.AttributeFactory, AttributeSource.State
 
Field Summary
 
Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
 
Constructor Summary
HunspellStemFilter(TokenStream input, HunspellDictionary dictionary)
          Creates a new HunspellStemFilter that will stem tokens from the given TokenStream using affix rules in the provided HunspellDictionary
HunspellStemFilter(TokenStream input, HunspellDictionary dictionary, boolean dedup)
          Creates a new HunspellStemFilter that will stem tokens from the given TokenStream using affix rules in the provided HunspellDictionary
 
Method Summary
 boolean incrementToken()
          Consumers (i.e., IndexWriter) use this method to advance the stream to the next token.
 void reset()
          Reset the filter as well as the input TokenStream.
 
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end
 
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
 

Constructor Detail

HunspellStemFilter

public HunspellStemFilter(TokenStream input,
                          HunspellDictionary dictionary)
Creates a new HunspellStemFilter that will stem tokens from the given TokenStream using affix rules in the provided HunspellDictionary

Parameters:
input - TokenStream whose tokens will be stemmed
dictionary - HunspellDictionary containing the affix rules and words that will be used to stem the tokens

HunspellStemFilter

public HunspellStemFilter(TokenStream input,
                          HunspellDictionary dictionary,
                          boolean dedup)
Creates a new HunspellStemFilter that will stem tokens from the given TokenStream using affix rules in the provided HunspellDictionary

Parameters:
input - TokenStream whose tokens will be stemmed
dictionary - HunspellDictionary containing the affix rules and words that will be used to stem the tokens
dedup - true if only unique terms should be output.
Method Detail

incrementToken

public boolean incrementToken()
                       throws IOException
Consumers (i.e., IndexWriter) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriate AttributeImpls with the attributes of the next token.

The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use AttributeSource.captureState() to create a copy of the current attribute state.

This method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to AttributeSource.addAttribute(Class) and AttributeSource.getAttribute(Class), references to all AttributeImpls that this stream uses should be retrieved during instantiation.

To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in TokenStream.incrementToken().

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

reset

public void reset()
           throws IOException
Reset the filter as well as the input TokenStream.

Overrides:
reset in class TokenFilter
Throws:
IOException


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