gate.creole.annic.apache.lucene.search
Class PhraseQuery

java.lang.Object
  gate.creole.annic.apache.lucene.search.Query
      gate.creole.annic.apache.lucene.search.PhraseQuery

All Implemented Interfaces:

Serializable, Cloneable

public class PhraseQuery
extends Query

A Query that matches documents containing a particular sequence of terms. This may be combined with other terms with a BooleanQuery.

See Also:

Serialized Form

Nested Class Summary

private class

PhraseQuery.PhraseWeight

Field Summary

private String	field
private Vector	positions
private int	slop
private Vector	terms
(package private) int	totalTerms

Constructor Summary

PhraseQuery()
Constructs an empty phrase query.

Method Summary

void	add(Term term)
void	add(Term term, Integer position, boolean considerAsATerm) Adds a term to the end of the query phrase.
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.
int	getSlop() Returns the slop.
Term[]	getTerms() Returns the set of terms in this phrase.
int	hashCode() Returns a hash code value for this object.
void	setSlop(int s) Sets the number of other words permitted between words in query phrase.
void	setTotalTerms(int totalTerms)
String	toString(String f) Prints a user-readable version of this query.

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

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

Methods inherited from class java.lang.Object

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

Field Detail

field

private String field

terms

private Vector terms

positions

private Vector positions

slop

private int slop

totalTerms

int totalTerms

Constructor Detail

PhraseQuery

public PhraseQuery()

Constructs an empty phrase query.

Method Detail

setSlop

public void setSlop(int s)

Sets the number of other words permitted between words in query phrase. If zero, then this is an exact phrase search. For larger values this works like a WITHIN or NEAR operator.

The slop is in fact an edit-distance, where the units correspond to moves of terms in the query phrase out of position. For example, to switch the order of two words requires two moves (the first move places the words atop one another), so to permit re-orderings of phrases, the slop must be at least two.

More exact matches are scored higher than sloppier matches, thus search results are sorted by exactness.

The slop is zero by default, requiring exact matches.

getSlop

public int getSlop()

Returns the slop. See setSlop().

add

public void add(Term term,
                Integer position,
                boolean considerAsATerm)

Adds a term to the end of the query phrase.

setTotalTerms

public void setTotalTerms(int totalTerms)

add

public void add(Term term)

getTerms

public Term[] getTerms()

Returns the set of terms in this phrase.

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

toString

public String toString(String f)

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