org.apache.lucene.search
Class ConstantScoreQuery.ConstantScorer

java.lang.Object
  extended by org.apache.lucene.search.DocIdSetIterator
      extended by org.apache.lucene.search.Scorer
          extended by 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:

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


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