Package org.apache.lucene.analysis.bn

Class BengaliNormalizationFilter

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.TokenFilter

org.apache.lucene.analysis.bn.BengaliNormalizationFilter

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public final class BengaliNormalizationFilter
extends TokenFilter

A TokenFilter that applies BengaliNormalizer to normalize the orthography.

In some cases the normalization may cause unrelated terms to conflate, so to prevent terms from being normalized use an instance of SetKeywordMarkerFilter or a custom TokenFilter that sets the KeywordAttribute before this TokenStream.

See Also:

BengaliNormalizer

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

AttributeSource.State

Field Summary

Fields

Modifier and Type	Field	Description
private KeywordAttribute	keywordAtt
private BengaliNormalizer	normalizer
private CharTermAttribute	termAtt

Fields inherited from class org.apache.lucene.analysis.TokenFilter

input

Fields inherited from class org.apache.lucene.analysis.TokenStream

DEFAULT_TOKEN_ATTRIBUTE_FACTORY

Constructor Summary

Constructors

Constructor	Description
BengaliNormalizationFilter(TokenStream input)

Method Summary

Modifier and Type	Method	Description
boolean	incrementToken()	Consumers (i.e., IndexWriter) use this method to advance the stream to the next token.

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, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

normalizer

private final BengaliNormalizer normalizer

termAtt

private final CharTermAttribute termAtt

keywordAtt

private final KeywordAttribute keywordAtt

Constructor Detail

BengaliNormalizationFilter

public BengaliNormalizationFilter(TokenStream input)

Method Detail

incrementToken

public boolean incrementToken()
                       throws java.io.IOException

Description copied from class: TokenStream

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:

java.io.IOException