org.apache.lucene.search
public abstract class SortComparator extends Object implements SortComparatorSource
This class should only be used if the other SortField types (SCORE, DOC, STRING, INT, FLOAT) do not provide an adequate sorting. It maintains an internal cache of values which could be quite large. The cache is an array of Comparable, one for each document in the index. There is a distinct Comparable for each unique term in the field - if some documents have the same term in the field, the cache array will have entries which reference the same Comparable.
Created: Apr 21, 2004 5:08:38 PM
Since: 1.4
Version: $Id: SortComparator.java 150541 2004-09-29 15:09:02Z goller $
Method Summary | |
---|---|
protected abstract Comparable | getComparable(String termtext)
Returns an object which, when sorted according to natural order,
will order the Term values in the correct order.
|
ScoreDocComparator | newComparator(IndexReader reader, String fieldname) |
For example, if the Terms contained integer values, this method
would return new Integer(termtext)
. Note that this
might not always be the most efficient implementation - for this
particular example, a better implementation might be to make a
ScoreDocLookupComparator that uses an internal lookup table of int.
Parameters: termtext The textual value of the term.
Returns: An object representing termtext
that sorts according to the natural order of termtext
.
See Also: Comparable ScoreDocComparator