org.apache.lucene.search

Class Query

public abstract class Query extends Object implements Serializable, Cloneable

The abstract base class for queries.

Instantiable subclasses are:

{@link TermQuery}
{@link MultiTermQuery}
{@link BooleanQuery}
{@link WildcardQuery}
{@link PhraseQuery}
{@link PrefixQuery}
{@link PhrasePrefixQuery}
{@link FuzzyQuery}
{@link RangeQuery}
{@link org.apache.lucene.search.spans.SpanQuery}

A parser for queries is contained in:

{@link org.apache.lucene.queryParser.QueryParser QueryParser}

Method Summary
Object	clone() Returns a clone of this query.
Query	combine(Query[] queries) Expert: called when re-writing queries under MultiSearcher.
protected Weight	createWeight(Searcher searcher) Expert: Constructs an appropriate Weight implementation for this query.
float	getBoost() Gets the boost for this clause.
Similarity	getSimilarity(Searcher searcher) Expert: Returns the Similarity implementation to be used for this query.
static Query	mergeBooleanQueries(Query[] 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`.
abstract String	toString(String field) Prints a query to a string, with `field` as the default field for terms.
String	toString() Prints a query to a string.
Weight	weight(Searcher searcher) Expert: Constructs an initializes a Weight for a top-level query.

Method Detail

clone

public Object clone()

Returns a clone of this query.

combine

public Query combine(Query[] queries)

Expert: called when re-writing queries under MultiSearcher.

Only implemented by derived queries, with no {@link #createWeight(Searcher)} implementatation.

createWeight

protected Weight createWeight(Searcher searcher)

Expert: Constructs an appropriate Weight implementation for this query.

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

getBoost

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.

getSimilarity

public Similarity getSimilarity(Searcher searcher)

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.

mergeBooleanQueries

public static Query mergeBooleanQueries(Query[] queries)

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

A utility for use by {@link #combine(Query[])} implementations.

rewrite

public Query rewrite(IndexReader reader)

Expert: called to re-write queries into primitive queries.

setBoost

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.

toString

public abstract String toString(String field)

Prints a query to a string, with field as the default field for terms.

The representation used is one that is readable by {@link org.apache.lucene.queryParser.QueryParser QueryParser} (although, if the query was created by the parser, the printed representation may not be exactly what was parsed).

toString

public String toString()

Prints a query to a string.

weight

public Weight weight(Searcher searcher)

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