org.apache.lucene.queries

Class TermsQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.queries.TermsQuery

All Implemented Interfaces:

Cloneable, Accountable

public class TermsQuery
extends Query
implements Accountable

Specialization for a disjunction over many terms that behaves like a ConstantScoreQuery over a BooleanQuery containing only BooleanClause.Occur.SHOULD clauses.

For instance in the following example, both @{code q1} and q2 would yield the same scores:

 Query q1 = new TermsQuery(new Term("field", "foo"), new Term("field", "bar"));

 BooleanQuery bq = new BooleanQuery();
 bq.add(new TermQuery(new Term("field", "foo")), Occur.SHOULD);
 bq.add(new TermQuery(new Term("field", "bar")), Occur.SHOULD);
 Query q2 = new ConstantScoreQuery(bq);
 

When there are few terms, this query executes like a regular disjunction. However, when there are many terms, instead of merging iterators on the fly, it will populate a bit set with matching docs and return a Scorer over this bit set.

NOTE: This query produces scores that are equal to its boost

Constructor Summary

Constructors

Constructor and Description
TermsQuery(List<Term> terms) Creates a new TermsQuery from the given list.
TermsQuery(String field, BytesRef... terms) Creates a new TermsQuery from the given BytesRef array for a single field.
TermsQuery(String field, List<BytesRef> terms) Creates a new TermsQuery from the given BytesRef list for a single field.
TermsQuery(Term... terms) Creates a new TermsQuery from the given array.

Method Summary

Methods

Modifier and Type	Method and Description
Weight	createWeight(IndexSearcher searcher, boolean needsScores) Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object obj)
Collection<Accountable>	getChildResources() Returns nested resources of this class.
int	hashCode()
long	ramBytesUsed() Return the memory usage of this object in bytes.
Query	rewrite(IndexReader reader) Expert: called to re-write queries into primitive queries.
String	toString(String defaultField) Prints a query to a string, with field assumed to be the default field and omitted.

Methods inherited from class org.apache.lucene.search.Query

clone, getBoost, setBoost, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

TermsQuery

public TermsQuery(List<Term> terms)

Creates a new TermsQuery from the given list. The list can contain duplicate terms and multiple fields.

TermsQuery

public TermsQuery(String field,
          List<BytesRef> terms)

Creates a new TermsQuery from the given BytesRef list for a single field.

TermsQuery

public TermsQuery(String field,
          BytesRef... terms)

Creates a new TermsQuery from the given BytesRef array for a single field.

TermsQuery

public TermsQuery(Term... terms)

Creates a new TermsQuery from the given array. The array can contain duplicate terms and multiple fields.

Method Detail

rewrite

public Query rewrite(IndexReader reader)
              throws IOException

Description copied from class: Query

Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.

Overrides:

rewrite in class Query

Throws:

IOException

equals

public boolean equals(Object obj)

Overrides:

equals in class Query

hashCode

public int hashCode()

Overrides:

hashCode in class Query

toString

public String toString(String defaultField)

Description copied from class: Query

Prints a query to a string, with field assumed to be the default field and omitted.

Specified by:

toString in class Query

ramBytesUsed

public long ramBytesUsed()

Description copied from interface: Accountable

Return the memory usage of this object in bytes. Negative values are illegal.

Specified by:

ramBytesUsed in interface Accountable

getChildResources

public Collection<Accountable> getChildResources()

Description copied from interface: Accountable

Returns nested resources of this class. The result should be a point-in-time snapshot (to avoid race conditions).

Specified by:

getChildResources in interface Accountable

See Also:

Accountables

createWeight

public Weight createWeight(IndexSearcher searcher,
                  boolean needsScores)
                    throws IOException

Description copied from class: Query

Expert: Constructs an appropriate Weight implementation for this query.

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

Overrides:

createWeight in class Query

needsScores - True if document scores (Scorer.score()) or match frequencies (Scorer.freq()) are needed.

Throws:

IOException