gate.creole.annic.apache.lucene.search

Class BooleanQuery

java.lang.Object

gate.creole.annic.apache.lucene.search.Query

gate.creole.annic.apache.lucene.search.BooleanQuery

All Implemented Interfaces:

Serializable, Cloneable

public class BooleanQuery
extends Query

A Query that matches documents matching boolean combinations of other queries, typically TermQuerys or PhraseQuerys.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BooleanQuery.TooManyClauses Thrown when an attempt is made to add more than getMaxClauseCount() clauses.

Field Summary

Fields

Modifier and Type	Field and Description
static int	maxClauseCount Default value is 1024.

Constructor Summary

Constructors

Constructor and Description
BooleanQuery() Constructs an empty boolean query.

Method Summary

Modifier and Type	Method and Description
void	add(BooleanClause clause) Adds a clause to a boolean query.
void	add(Query query, boolean required, boolean prohibited) Adds a clause to a boolean query.
Object	clone() Returns a clone of this query.
protected Weight	createWeight(Searcher searcher) Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object o) Returns true iff o is equal to this.
BooleanClause[]	getClauses() Returns the set of clauses in this query.
static int	getMaxClauseCount() Return the maximum number of clauses permitted, 1024 by default.
int	hashCode() Returns a hash code value for this object.
Query	rewrite(IndexReader reader) Expert: called to re-write queries into primitive queries.
static void	setMaxClauseCount(int maxClauseCount) Set the maximum number of clauses permitted.
String	toString(String field) Prints a user-readable version of this query.

Methods inherited from class gate.creole.annic.apache.lucene.search.Query

combine, getBoost, getSimilarity, mergeBooleanQueries, setBoost, toString, weight

Methods inherited from class java.lang.Object

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

Field Detail

maxClauseCount

public static int maxClauseCount

Default value is 1024. Use gate.creole.annic.apache.lucene.maxClauseCount system property to override.

Constructor Detail

BooleanQuery

public BooleanQuery()

Constructs an empty boolean query.

Method Detail

getMaxClauseCount

public static int getMaxClauseCount()

Return the maximum number of clauses permitted, 1024 by default. Attempts to add more than the permitted number of clauses cause BooleanQuery.TooManyClauses to be thrown.

setMaxClauseCount

public static void setMaxClauseCount(int maxClauseCount)

Set the maximum number of clauses permitted.

add

public void add(Query query,
                boolean required,
                boolean prohibited)

Adds a clause to a boolean query. Clauses may be:

• required which means that documents which do not match this sub-query will not match the boolean query;
• prohibited which means that documents which do match this sub-query will not match the boolean query; or
• neither, in which case matched documents are neither prohibited from nor required to match the sub-query. However, a document must match at least 1 sub-query to match the boolean query.

It is an error to specify a clause as both required and prohibited.

See Also:

getMaxClauseCount()

add

public void add(BooleanClause clause)

Adds a clause to a boolean query.

See Also:

getMaxClauseCount()

getClauses

public BooleanClause[] getClauses()

Returns the set of clauses in this query.

createWeight

protected Weight createWeight(Searcher searcher)

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

rewrite

public Query rewrite(IndexReader reader)
              throws IOException

Description copied from class: Query

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

Overrides:

rewrite in class Query

Throws:

IOException

clone

public Object clone()

Description copied from class: Query

Returns a clone of this query.

Overrides:

clone in class Query

toString

public String toString(String field)

Prints a user-readable version of this query.

Specified by:

toString in class Query

equals

public boolean equals(Object o)

Returns true iff o is equal to this.

Overrides:

equals in class Object

hashCode

public int hashCode()

Returns a hash code value for this object.

Overrides:

hashCode in class Object