org.apache.lucene.search
Class SortComparator
java.lang.Object
org.apache.lucene.search.SortComparator
- Serializable, SortComparatorSource
public abstract class SortComparator
extends java.lang.Object
Abstract base class for sorting hits returned by a Query.
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
$Id: SortComparator.java,v 1.2.2.1 2004/09/30 19:20:16 dnaber Exp $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) - Creates a comparator for the field in the given index.
|
getComparable
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.
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.
termtext
- The textual value of the term.
- An object representing
termtext
that sorts according to the natural order of termtext
.
newComparator
public ScoreDocComparator newComparator(IndexReader reader,
String fieldname)
throws IOException
Creates a comparator for the field in the given index.
- newComparator in interface SortComparatorSource
reader
- Index to create comparator for.fieldname
- Field to create comparator for.
- Comparator of ScoreDoc objects.
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