org.apache.lucene.search
Class ConstantScoreQuery.ConstantScorer

java.lang.Object
  org.apache.lucene.search.Scorer
      org.apache.lucene.search.ConstantScoreQuery.ConstantScorer

Enclosing class:

ConstantScoreQuery

protected class ConstantScoreQuery.ConstantScorer
extends Scorer

Constructor Summary

ConstantScoreQuery.ConstantScorer(Similarity similarity, IndexReader reader, Weight w)

Method Summary

int	doc() Returns the current document number matching the query.
Explanation	explain(int doc) Returns an explanation of the score for a document.
boolean	next() Advances to the document matching this Scorer with the lowest doc Id greater than the current value of Scorer.doc() (or to the matching document with the lowest doc Id if next has never been called on this Scorer).
float	score() Returns the score of the current document matching the query.
boolean	skipTo(int target) Skips to the document matching this Scorer with the lowest doc Id greater than or equal to a given target.

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

getSimilarity, score, score

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConstantScoreQuery.ConstantScorer

public ConstantScoreQuery.ConstantScorer(Similarity similarity,
                                         IndexReader reader,
                                         Weight w)
                                  throws java.io.IOException

Throws:

java.io.IOException

Method Detail

next

public boolean next()
             throws java.io.IOException

Description copied from class: Scorer

Advances to the document matching this Scorer with the lowest doc Id greater than the current value of Scorer.doc() (or to the matching document with the lowest doc Id if next has never been called on this Scorer).

When this method is used the Scorer.explain(int) method should not be used.

Specified by:

next in class Scorer

Returns:

true iff there is another document matching the query.

Throws:

java.io.IOException

See Also:

BooleanQuery.setAllowDocsOutOfOrder(boolean)

doc

public int doc()

Description copied from class: Scorer

Returns the current document number matching the query. Initially invalid, until Scorer.next() is called the first time.

Specified by:

doc in class Scorer

score

public float score()
            throws java.io.IOException

Description copied from class: Scorer

Returns the score of the current document matching the query. Initially invalid, until Scorer.next() or Scorer.skipTo(int) is called the first time.

Specified by:

score in class Scorer

Throws:

java.io.IOException

skipTo

public boolean skipTo(int target)
               throws java.io.IOException

Description copied from class: Scorer

Skips to the document matching this Scorer with the lowest doc Id greater than or equal to a given target.

The behavior of this method is undefined if the target specified is less than or equal to the current value of Scorer.doc().

Behaves as if written:

   boolean skipTo(int target) {
     do {
       if (!next())
             return false;
     } while (target > doc());
     return true;
   }
 

Most implementations are considerably more efficient than that.

When this method is used the Scorer.explain(int) method should not be used.

Specified by:

skipTo in class Scorer

Parameters:

target - The target document number.

Returns:

true iff there is such a match.

Throws:

java.io.IOException

See Also:

BooleanQuery.setAllowDocsOutOfOrder(boolean)

explain

public Explanation explain(int doc)
                    throws java.io.IOException

Description copied from class: Scorer

Returns an explanation of the score for a document.
When this method is used, the Scorer.next(), Scorer.skipTo(int) and Scorer.score(HitCollector) methods should not be used.

Specified by:

explain in class Scorer

Parameters:

doc - The document number for the explanation.

Throws:

java.io.IOException