org.apache.lucene.search

Class SortComparator

java.lang.Object

org.apache.lucene.search.SortComparator

All Implemented Interfaces:

java.io.Serializable, SortComparatorSource

public abstract class SortComparator
extends java.lang.Object
implements SortComparatorSource

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

Since:

1.4

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SortComparator()

Method Summary

Modifier and Type	Method and Description
ScoreDocComparator	newComparator(IndexReader reader, java.lang.String fieldname) Creates a comparator for the field in the given index.

Methods inherited from class java.lang.Object

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

Constructor Detail

SortComparator

public SortComparator()

Method Detail

newComparator

public ScoreDocComparator newComparator(IndexReader reader,
                                        java.lang.String fieldname)
                                 throws java.io.IOException

Description copied from interface: SortComparatorSource

Creates a comparator for the field in the given index.

Specified by:

newComparator in interface SortComparatorSource

Parameters:

reader - Index to create comparator for.

fieldname - Name of the field to create comparator for.

Returns:

Comparator of ScoreDoc objects.

Throws:

java.io.IOException - If an error occurs reading the index.