| java.lang.Object | ||
| ↳ | org.apache.lucene.search.Query | |
| ↳ | org.apache.lucene.search.function.ValueSourceQuery | |
 Known Direct Subclasses
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Class Overview
Expert: A Query that sets the scores of document to the
values obtained from a ValueSource.
This query provides a score for each and every undeleted document in the index.
The value source can be based on a (cached) value of an indexed field, but it can also be based on an external source, e.g. values read from an external database.
Score is set as: Score(doc,query) = query.getBoost()2 * valueSource(doc).
WARNING: The status of the search.function package is experimental. The APIs introduced here might change in the future and will not be supported anymore in such a case.
Summary
| Public Constructors | |||||||||||
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Create a value source query
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| Public Methods | |||||||||||
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Expert: Constructs an appropriate Weight implementation for this query.
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Returns true if
o is equal to this. | |||||||||||
Expert: adds all terms occurring in this query to the terms set.
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Returns a hash code value for this object.
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Expert: called to re-write queries into primitive queries.
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Prints a query to a string, with
field assumed to be the
default field and omitted. | |||||||||||
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Inherited Methods | |||||||||||
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From class
org.apache.lucene.search.Query
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From class
java.lang.Object
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Public Constructors
public ValueSourceQuery (ValueSource valSrc)
Create a value source query
Parameters
| valSrc | provides the values defines the function to be used for scoring |
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Public Methods
public Weight createWeight (Searcher searcher)
Expert: Constructs an appropriate Weight implementation for this query.
Only implemented by primitive queries, which re-write to themselves.
public void extractTerms (Set<Term> terms)
Expert: adds all terms occurring in this query to the terms set. Only
works if this query is in its rewritten form.
public int hashCode ()
Returns a hash code value for this object.
public Query rewrite (IndexReader reader)
Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.
Throws
| IOException |
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public String toString (String field)
Prints a query to a string, with field assumed to be the
default field and omitted.
The representation used is one that is supposed to be readable
by QueryParser. However,
there are the following limitations:
- If the query was created by the parser, the printed representation may not be exactly what was parsed. For example, characters that need to be escaped will be represented without the required backslash.
- Some of the more complicated queries (e.g. span queries) don't have a representation that can be parsed by QueryParser.