Package org.apache.lucene.search
Class Query
- java.lang.Object
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- org.apache.lucene.search.Query
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- Direct Known Subclasses:
BlendedTermQuery
,BooleanQuery
,BoostQuery
,ConstantScoreQuery
,DisjunctionMaxQuery
,FieldExistsQuery
,IndexOrDocValuesQuery
,IndexSortSortedNumericDocValuesRangeQuery
,IndriQuery
,KnnByteVectorQuery
,KnnFloatVectorQuery
,MatchAllDocsQuery
,MatchNoDocsQuery
,MultiPhraseQuery
,MultiTermQuery
,NGramPhraseQuery
,PhraseQuery
,PointInSetQuery
,PointRangeQuery
,RangeFieldQuery
,SynonymQuery
,TermQuery
,XYDocValuesPointInGeometryQuery
public abstract class Query extends Object
The abstract base class for queries.Instantiable subclasses are:
TermQuery
BooleanQuery
WildcardQuery
PhraseQuery
PrefixQuery
MultiPhraseQuery
FuzzyQuery
RegexpQuery
TermRangeQuery
PointRangeQuery
ConstantScoreQuery
DisjunctionMaxQuery
MatchAllDocsQuery
See also additional queries available in the Queries module
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Constructor Summary
Constructors Constructor Description Query()
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected int
classHash()
Provides a constant integer for a given class, derived from the name of the class.Weight
createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost)
Expert: Constructs an appropriate Weight implementation for this query.abstract boolean
equals(Object obj)
Override and implement query instance equivalence properly in a subclass.abstract int
hashCode()
Override and implement query hash code properly in a subclass.Query
rewrite(IndexReader reader)
Expert: called to re-write queries into primitive queries.protected boolean
sameClassAs(Object other)
Utility method to check whetherother
is not null and is exactly of the same class as this object's class.String
toString()
Prints a query to a string.abstract String
toString(String field)
Prints a query to a string, withfield
assumed to be the default field and omitted.abstract void
visit(QueryVisitor visitor)
Recurse through the query tree, visiting any child queries
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Method Detail
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toString
public abstract String toString(String field)
Prints a query to a string, withfield
assumed to be the default field and omitted.
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toString
public final String toString()
Prints a query to a string.
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createWeight
public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException
Expert: Constructs an appropriate Weight implementation for this query.Only implemented by primitive queries, which re-write to themselves.
- Parameters:
scoreMode
- How the produced scorers will be consumed.boost
- The boost that is propagated by the parent queries.- Throws:
IOException
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rewrite
public Query rewrite(IndexReader reader) throws IOException
Expert: 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
rewrite
multiple times if necessary, until the rewritten query is the same as the original query.- Throws:
IOException
- See Also:
IndexSearcher.rewrite(Query)
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visit
public abstract void visit(QueryVisitor visitor)
Recurse through the query tree, visiting any child queries- Parameters:
visitor
- a QueryVisitor to be called by each query in the tree
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equals
public abstract boolean equals(Object obj)
Override and implement query instance equivalence properly in a subclass. This is required so thatQueryCache
works 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 that other instance. Utility methods are provided for certain repetitive code.
- Overrides:
equals
in classObject
- See Also:
sameClassAs(Object)
,classHash()
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hashCode
public abstract int hashCode()
Override and implement query hash code properly in a subclass. This is required so thatQueryCache
works properly.- Overrides:
hashCode
in classObject
- See Also:
equals(Object)
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sameClassAs
protected final boolean sameClassAs(Object other)
Utility method to check whetherother
is not null and is exactly of the same class as this object's class.When this method is used in an implementation of
equals(Object)
, consider usingclassHash()
in the implementation ofhashCode()
to differentiate different class
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classHash
protected final int classHash()
Provides a constant integer for a given class, derived from the name of the class. The rationale for not using justObject.hashCode()
is that classes may be assigned different hash codes for each execution and we want hashes to be possibly consistent to facilitate debugging.
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