Class ConstantScoreQuery
- java.lang.Object
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- org.apache.lucene.search.Query
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- org.apache.lucene.search.ConstantScoreQuery
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public final class ConstantScoreQuery extends Query
A query that wraps another query and simply returns a constant score equal to 1 for every document that matches the query. It therefore simply strips of all scores and always returns 1.
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Nested Class Summary
Nested Classes Modifier and Type Class Description protected static classConstantScoreQuery.ConstantBulkScorerWe return this as ourBulkScorerso that if the CSQ wraps a query with its own optimized top-level scorer (e.g.
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Constructor Summary
Constructors Constructor Description ConstantScoreQuery(Query query)Strips off scores from the passed in Query.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description WeightcreateWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost)Expert: Constructs an appropriate Weight implementation for this query.booleanequals(Object other)Override and implement query instance equivalence properly in a subclass.QuerygetQuery()Returns the encapsulated query.inthashCode()Override and implement query hash code properly in a subclass.Queryrewrite(IndexSearcher indexSearcher)Expert: called to re-write queries into primitive queries.StringtoString(String field)Prints a query to a string, withfieldassumed to be the default field and omitted.voidvisit(QueryVisitor visitor)Recurse through the query tree, visiting any child queries.-
Methods inherited from class org.apache.lucene.search.Query
classHash, rewrite, sameClassAs, toString
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Constructor Detail
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ConstantScoreQuery
public ConstantScoreQuery(Query query)
Strips off scores from the passed in Query. The hits will get a constant score of 1.
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Method Detail
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getQuery
public Query getQuery()
Returns the encapsulated query.
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rewrite
public Query rewrite(IndexSearcher indexSearcher) throws IOException
Description copied from class:QueryExpert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.Callers are expected to call
rewritemultiple times if necessary, until the rewritten query is the same as the original query.The rewrite process may be able to make use of IndexSearcher's executor and be executed in parallel if the executor is provided.
However, if any of the intermediary queries do not satisfy the new API, parallel rewrite is not possible for any subsequent sub-queries. To take advantage of this API, the entire query tree must override this method.
- Overrides:
rewritein classQuery- Throws:
IOException- See Also:
IndexSearcher.rewrite(Query)
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visit
public void visit(QueryVisitor visitor)
Description copied from class:QueryRecurse through the query tree, visiting any child queries.
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createWeight
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException
Description copied from class:QueryExpert: Constructs an appropriate Weight implementation for this query.Only implemented by primitive queries, which re-write to themselves.
- Overrides:
createWeightin classQueryscoreMode- How the produced scorers will be consumed.boost- The boost that is propagated by the parent queries.- Throws:
IOException
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toString
public String toString(String field)
Description copied from class:QueryPrints a query to a string, withfieldassumed to be the default field and omitted.
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equals
public boolean equals(Object other)
Description copied from class:QueryOverride and implement query instance equivalence properly in a subclass. This is required so thatQueryCacheworks properly.Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical to those of the other instance. Utility methods are provided for certain repetitive code.
- Specified by:
equalsin classQuery- See Also:
Query.sameClassAs(Object),Query.classHash()
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hashCode
public int hashCode()
Description copied from class:QueryOverride and implement query hash code properly in a subclass. This is required so thatQueryCacheworks properly.- Specified by:
hashCodein classQuery- See Also:
Query.equals(Object)
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