org.apache.lucene.search.grouping

Class TopGroupsCollector<T>

java.lang.Object

org.apache.lucene.search.SimpleCollector

org.apache.lucene.search.grouping.SecondPassGroupingCollector<T>

org.apache.lucene.search.grouping.TopGroupsCollector<T>

Type Parameters:

T - the type of the group value

All Implemented Interfaces:

Collector, LeafCollector

public class TopGroupsCollector<T>
extends SecondPassGroupingCollector<T>

A second-pass collector that collects the TopDocs for each group, and returns them as a TopGroups object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	TopGroupsCollector.MaxScoreCollector
private static class	TopGroupsCollector.TopDocsAndMaxScoreCollector
private static class	TopGroupsCollector.TopDocsReducer<T>

Field Summary

Fields

Modifier and Type	Field and Description
private Sort	groupSort
private int	maxDocsPerGroup
private Sort	withinGroupSort

Fields inherited from class org.apache.lucene.search.grouping.SecondPassGroupingCollector

groupReducer, groups, groupSelector, totalGroupedHitCount, totalHitCount

Constructor Summary

Constructors

Constructor and Description
TopGroupsCollector(GroupSelector<T> groupSelector, java.util.Collection<SearchGroup<T>> groups, Sort groupSort, Sort withinGroupSort, int maxDocsPerGroup, boolean getMaxScores) Create a new TopGroupsCollector

Method Summary

Modifier and Type	Method and Description
TopGroups<T>	getTopGroups(int withinGroupOffset) Get the TopGroups recorded by this collector

Methods inherited from class org.apache.lucene.search.grouping.SecondPassGroupingCollector

collect, doSetNextReader, getGroupSelector, scoreMode, setScorer

Methods inherited from class org.apache.lucene.search.SimpleCollector

getLeafCollector

Methods inherited from class java.lang.Object

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

Field Detail

groupSort

private final Sort groupSort

withinGroupSort

private final Sort withinGroupSort

maxDocsPerGroup

private final int maxDocsPerGroup

Constructor Detail

TopGroupsCollector

public TopGroupsCollector(GroupSelector<T> groupSelector,
                          java.util.Collection<SearchGroup<T>> groups,
                          Sort groupSort,
                          Sort withinGroupSort,
                          int maxDocsPerGroup,
                          boolean getMaxScores)

Create a new TopGroupsCollector

Parameters:

groupSelector - the group selector used to define groups

groups - the groups to collect TopDocs for

groupSort - the order in which groups are returned

withinGroupSort - the order in which documents are sorted in each group

maxDocsPerGroup - the maximum number of docs to collect for each group

getMaxScores - if true, record the maximum score for each group

Method Detail

getTopGroups

public TopGroups<T> getTopGroups(int withinGroupOffset)

Get the TopGroups recorded by this collector

Parameters:

withinGroupOffset - the offset within each group to start collecting documents