org.apache.lucene.search
Class ConstantScoreQuery.ConstantScorer

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

Enclosing class:

ConstantScoreQuery

protected class ConstantScoreQuery.ConstantScorer
extends Scorer

Field Summary

Fields inherited from class org.apache.lucene.search.DocIdSetIterator

NO_MORE_DOCS

Constructor Summary

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

Method Summary

int	advance(int target) Advances to the first beyond the current whose document number is greater than or equal to target.
int	doc() Deprecated. use docID() instead.
int	docID() Returns the following: -1 or DocIdSetIterator.NO_MORE_DOCS if DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) were not called yet.
Explanation	explain(int doc) Returns an explanation of the score for a document.
boolean	next() Deprecated. use nextDoc() instead.
int	nextDoc() Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set. NOTE: in 3.0 this method will become abstract, following the removal of DocIdSetIterator.next().
float	score() Returns the score of the current document matching the query.
boolean	skipTo(int target) Deprecated. use advance(int) instead.

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

getSimilarity, score, score, 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 IOException

Throws:

IOException

Method Detail

next

public boolean next()
             throws IOException

Deprecated. use nextDoc() instead.

Description copied from class: DocIdSetIterator

Unsupported anymore. Call DocIdSetIterator.nextDoc() instead. This method throws UnsupportedOperationException if called.

Overrides:

next in class DocIdSetIterator

Throws:

IOException

nextDoc

public int nextDoc()
            throws IOException

Description copied from class: DocIdSetIterator

Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set.
NOTE: in 3.0 this method will become abstract, following the removal of DocIdSetIterator.next(). For backward compatibility it is implemented as:

 public int nextDoc() throws IOException {
   return next() ? doc() : NO_MORE_DOCS;
 }
 

NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.

Overrides:

nextDoc in class DocIdSetIterator

Throws:

IOException

doc

public int doc()

Deprecated. use docID() instead.

Description copied from class: DocIdSetIterator

Unsupported anymore. Call DocIdSetIterator.docID() instead. This method throws UnsupportedOperationException if called.

Overrides:

doc in class DocIdSetIterator

docID

public int docID()

Description copied from class: DocIdSetIterator

Returns the following:

• -1 or DocIdSetIterator.NO_MORE_DOCS if DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) were not called yet.
• DocIdSetIterator.NO_MORE_DOCS if the iterator has exhausted.
• Otherwise it should return the doc ID it is currently on.

NOTE: in 3.0, this method will become abstract.

Overrides:

docID in class DocIdSetIterator

score

public float score()
            throws IOException

Description copied from class: Scorer

Returns the score of the current document matching the query. Initially invalid, until DocIdSetIterator.next() or DocIdSetIterator.skipTo(int) is called the first time, or when called from within Collector.collect(int).

Specified by:

score in class Scorer

Throws:

IOException

skipTo

public boolean skipTo(int target)
               throws IOException

Deprecated. use advance(int) instead.

Description copied from class: DocIdSetIterator

Unsupported anymore. Call DocIdSetIterator.advance(int) instead. This method throws UnsupportedOperationException if called.

Overrides:

skipTo in class DocIdSetIterator

Throws:

IOException

advance

public int advance(int target)
            throws IOException

Description copied from class: DocIdSetIterator

Advances to the first beyond the current whose document number is greater than or equal to target. Returns the current document number or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set.

Behaves as if written:

 int advance(int target) {
   int doc;
   while ((doc = nextDoc()) < target) {
   }
   return doc;
 }
 

Some implementations are considerably more efficient than that.

NOTE: certain implementations may return a different value (each time) if called several times in a row with the same target.

NOTE: this method may be called with 2147483647 for efficiency by some Scorers. If your implementation cannot efficiently determine that it should exhaust, it is recommended that you check for that value in each call to this method.

NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.

NOTE: in 3.0 this method will become abstract, following the removal of DocIdSetIterator.skipTo(int).

Overrides:

advance in class DocIdSetIterator

Throws:

IOException

explain

public Explanation explain(int doc)
                    throws IOException

Description copied from class: Scorer

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

Overrides:

explain in class Scorer

Parameters:

doc - The document number for the explanation.

Throws:

IOException