Package org.apache.lucene.search.highlight

Class WeightedSpanTermExtractor

java.lang.Object

org.apache.lucene.search.highlight.WeightedSpanTermExtractor

public class WeightedSpanTermExtractor
extends Object

Class used to extract WeightedSpanTerms from a Query based on whether Terms from the Query are contained in a supplied TokenStream.

Constructor Summary

Constructors

Constructor	Description
WeightedSpanTermExtractor()
WeightedSpanTermExtractor(String defaultField)

Method Summary

Modifier and Type	Method	Description
boolean	getExpandMultiTermQuery()
TokenStream	getTokenStream()
Map<String,WeightedSpanTerm>	getWeightedSpanTerms(Query query, TokenStream tokenStream)	Creates a Map of WeightedSpanTerms from the given Query and TokenStream.
Map<String,WeightedSpanTerm>	getWeightedSpanTerms(Query query, TokenStream tokenStream, String fieldName)	Creates a Map of WeightedSpanTerms from the given Query and TokenStream.
Map<String,WeightedSpanTerm>	getWeightedSpanTermsWithScores(Query query, TokenStream tokenStream, String fieldName, IndexReader reader)	Creates a Map of WeightedSpanTerms from the given Query and TokenStream.
boolean	isCachedTokenStream()
void	setExpandMultiTermQuery(boolean expandMultiTermQuery)
void	setWrapIfNotCachingTokenFilter(boolean wrap)	By default, TokenStreams that are not of the type CachingTokenFilter are wrapped in a CachingTokenFilter to ensure an efficient reset - if you are already using a different caching TokenStream impl and you don't want it to be wrapped, set this to false.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WeightedSpanTermExtractor

public WeightedSpanTermExtractor()

WeightedSpanTermExtractor

public WeightedSpanTermExtractor(String defaultField)

Method Detail

getWeightedSpanTerms

public Map<String,WeightedSpanTerm> getWeightedSpanTerms(Query query,
                                                               TokenStream tokenStream)
                                                        throws IOException

Creates a Map of WeightedSpanTerms from the given Query and TokenStream.

Parameters:

query - that caused hit

tokenStream - of text to be highlighted

Returns:

Map containing WeightedSpanTerms

Throws:

IOException - If there is a low-level I/O error

getWeightedSpanTerms

public Map<String,WeightedSpanTerm> getWeightedSpanTerms(Query query,
                                                               TokenStream tokenStream,
                                                               String fieldName)
                                                        throws IOException

Creates a Map of WeightedSpanTerms from the given Query and TokenStream.

Parameters:

query - that caused hit

tokenStream - of text to be highlighted

fieldName - restricts Term's used based on field name

Returns:

Map containing WeightedSpanTerms

Throws:

IOException - If there is a low-level I/O error

getWeightedSpanTermsWithScores

public Map<String,WeightedSpanTerm> getWeightedSpanTermsWithScores(Query query,
                                                                         TokenStream tokenStream,
                                                                         String fieldName,
                                                                         IndexReader reader)
                                                                  throws IOException

Creates a Map of WeightedSpanTerms from the given Query and TokenStream. Uses a supplied IndexReader to properly weight terms (for gradient highlighting).

Parameters:

query - that caused hit

tokenStream - of text to be highlighted

fieldName - restricts Term's used based on field name

reader - to use for scoring

Returns:

Map of WeightedSpanTerms with quasi tf/idf scores

Throws:

IOException - If there is a low-level I/O error

getExpandMultiTermQuery

public boolean getExpandMultiTermQuery()

setExpandMultiTermQuery

public void setExpandMultiTermQuery(boolean expandMultiTermQuery)

isCachedTokenStream

public boolean isCachedTokenStream()

getTokenStream

public TokenStream getTokenStream()

setWrapIfNotCachingTokenFilter

public void setWrapIfNotCachingTokenFilter(boolean wrap)

By default, TokenStreams that are not of the type CachingTokenFilter are wrapped in a CachingTokenFilter to ensure an efficient reset - if you are already using a different caching TokenStream impl and you don't want it to be wrapped, set this to false.