public abstract class

Query

extends Object
implements Serializable Cloneable
java.lang.Object
   ↳ org.apache.lucene.search.Query
Known Direct Subclasses
Known Indirect Subclasses

Class Overview

The abstract base class for queries.

Instantiable subclasses are:

A parser for queries is contained in:

Summary

Public Constructors
Query()
Public Methods
Object clone()
Returns a clone of this query.
Query combine(Query[] queries)
Expert: called when re-writing queries under MultiSearcher.
Weight createWeight(Searcher searcher)
Expert: Constructs an appropriate Weight implementation for this query.
boolean equals(Object obj)
void extractTerms(Set<Term> terms)
Expert: adds all terms occurring in this query to the terms set.
float getBoost()
Gets the boost for this clause.
@Deprecated Similarity getSimilarity(Searcher searcher)
This method is deprecated. Instead of using "runtime" subclassing/delegation, subclass the Weight instead.
int hashCode()
static Query mergeBooleanQueries(BooleanQuery... queries)
Expert: merges the clauses of a set of BooleanQuery's into a single BooleanQuery.
Query rewrite(IndexReader reader)
Expert: called to re-write queries into primitive queries.
void setBoost(float b)
Sets the boost for this query clause to b.
String toString()
Prints a query to a string.
abstract String toString(String field)
Prints a query to a string, with field assumed to be the default field and omitted.
Weight weight(Searcher searcher)
Expert: Constructs and initializes a Weight for a top-level query.
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public Query ()

Public Methods

public Object clone ()

Returns a clone of this query.

public Query combine (Query[] queries)

Expert: called when re-writing queries under MultiSearcher. Create a single query suitable for use by all subsearchers (in 1-1 correspondence with queries). This is an optimization of the OR of all queries. We handle the common optimization cases of equal queries and overlapping clauses of boolean OR queries (as generated by MultiTermQuery.rewrite()). Be careful overriding this method as queries[0] determines which method will be called and is not necessarily of the same type as the other queries.

public Weight createWeight (Searcher searcher)

Expert: Constructs an appropriate Weight implementation for this query.

Only implemented by primitive queries, which re-write to themselves.

Throws
IOException

public boolean equals (Object obj)

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.

Throws
UnsupportedOperationException if this query is not yet rewritten

public float getBoost ()

Gets the boost for this clause. Documents matching this clause will (in addition to the normal weightings) have their score multiplied by b. The boost is 1.0 by default.

@Deprecated public Similarity getSimilarity (Searcher searcher)

This method is deprecated.
Instead of using "runtime" subclassing/delegation, subclass the Weight instead.

Expert: Returns the Similarity implementation to be used for this query. Subclasses may override this method to specify their own Similarity implementation, perhaps one that delegates through that of the Searcher. By default the Searcher's Similarity implementation is returned.

public int hashCode ()

public static Query mergeBooleanQueries (BooleanQuery... queries)

Expert: merges the clauses of a set of BooleanQuery's into a single BooleanQuery.

A utility for use by combine(Query[]) implementations.

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

public void setBoost (float b)

Sets the boost for this query clause to b. Documents matching this clause will (in addition to the normal weightings) have their score multiplied by b.

public String toString ()

Prints a query to a string.

public abstract 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.

public Weight weight (Searcher searcher)

Expert: Constructs and initializes a Weight for a top-level query.

Throws
IOException