org.apache.lucene.search.highlight

Class QueryTermExtractor

public final class QueryTermExtractor extends Object

Utility class used to extract the terms used in a query, plus any weights. This class will not find terms for MultiTermQuery, RangeQuery and PrefixQuery classes so the caller must pass a rewritten query (see Query.rewrite) to obtain a list of expanded terms.
Method Summary
static WeightedTerm[]getIdfWeightedTerms(Query query, IndexReader reader, String fieldName)
Extracts all terms texts of a given Query into an array of WeightedTerms
static WeightedTerm[]getTerms(Query query)
Extracts all terms texts of a given Query into an array of WeightedTerms
static WeightedTerm[]getTerms(Query query, boolean prohibited, String fieldName)
Extracts all terms texts of a given Query into an array of WeightedTerms
static WeightedTerm[]getTerms(Query query, boolean prohibited)
Extracts all terms texts of a given Query into an array of WeightedTerms

Method Detail

getIdfWeightedTerms

public static final WeightedTerm[] getIdfWeightedTerms(Query query, IndexReader reader, String fieldName)
Extracts all terms texts of a given Query into an array of WeightedTerms

Parameters: query Query to extract term texts from reader used to compute IDF which can be used to a) score selected fragments better b) use graded highlights eg chaning intensity of font color fieldName the field on which Inverse Document Frequency (IDF) calculations are based

Returns: an array of the terms used in a query, plus their weights.

getTerms

public static final WeightedTerm[] getTerms(Query query)
Extracts all terms texts of a given Query into an array of WeightedTerms

Parameters: query Query to extract term texts from

Returns: an array of the terms used in a query, plus their weights.

getTerms

public static final WeightedTerm[] getTerms(Query query, boolean prohibited, String fieldName)
Extracts all terms texts of a given Query into an array of WeightedTerms

Parameters: query Query to extract term texts from prohibited true to extract "prohibited" terms, too fieldName The fieldName used to filter query terms

Returns: an array of the terms used in a query, plus their weights.

getTerms

public static final WeightedTerm[] getTerms(Query query, boolean prohibited)
Extracts all terms texts of a given Query into an array of WeightedTerms

Parameters: query Query to extract term texts from prohibited true to extract "prohibited" terms, too

Returns: an array of the terms used in a query, plus their weights.

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