org.apache.lucene.search

Class FilteredDocIdSetIterator

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.search.FilteredDocIdSetIterator

public abstract class FilteredDocIdSetIterator
extends DocIdSetIterator

Abstract decorator class of a DocIdSetIterator implementation that provides on-demand filter/validation mechanism on an underlying DocIdSetIterator. See FilteredDocIdSet.

Field Summary

Fields

Modifier and Type	Field and Description
protected DocIdSetIterator	_innerIter

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

NO_MORE_DOCS

Constructor Summary

Constructors

Constructor and Description
FilteredDocIdSetIterator(DocIdSetIterator innerIter) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
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.
protected abstract boolean	match(int doc) Validation method to determine whether a docid should be in the result set.
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().
boolean	skipTo(int n) Deprecated. use advance(int) instead.

Methods inherited from class java.lang.Object

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

Field Detail

_innerIter

protected DocIdSetIterator _innerIter

Constructor Detail

FilteredDocIdSetIterator

public FilteredDocIdSetIterator(DocIdSetIterator innerIter)

Constructor.

Parameters:

innerIter - Underlying DocIdSetIterator.

Method Detail

match

protected abstract boolean match(int doc)
                          throws IOException

Validation method to determine whether a docid should be in the result set.

Parameters:

doc - docid to be tested

Returns:

true if input docid should be in the result set, false otherwise.

Throws:

IOException

See Also:

FilteredDocIdSetIterator(DocIdSetIterator).

doc

public final 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

next

public final 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

skipTo

public final boolean skipTo(int n)
                     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