org.apache.lucene.search.grouping

Class DistinctValuesCollector<T,R>

java.lang.Object

org.apache.lucene.search.SimpleCollector

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

org.apache.lucene.search.grouping.DistinctValuesCollector<T,R>

All Implemented Interfaces:

Collector, LeafCollector

public class DistinctValuesCollector<T,R>
extends SecondPassGroupingCollector<T>

A second pass grouping collector that keeps track of distinct values for a specified field for the top N group.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DistinctValuesCollector.GroupCount<T,R> Returned by getGroups(), representing the value and set of distinct values for the group.

Field Summary

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

groupReducer, groups, groupSelector, totalGroupedHitCount, totalHitCount

Constructor Summary

Constructors

Constructor and Description
DistinctValuesCollector(GroupSelector<T> groupSelector, java.util.Collection<SearchGroup<T>> groups, GroupSelector<R> valueSelector) Create a DistinctValuesCollector

Method Summary

Modifier and Type	Method and Description
java.util.List<DistinctValuesCollector.GroupCount<T,R>>	getGroups() Returns all unique values for each top N group.

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

collect, doSetNextReader, getGroupSelector, needsScores, 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

Constructor Detail

DistinctValuesCollector

public DistinctValuesCollector(GroupSelector<T> groupSelector,
                               java.util.Collection<SearchGroup<T>> groups,
                               GroupSelector<R> valueSelector)

Create a DistinctValuesCollector

Parameters:

groupSelector - the group selector to determine the top-level groups

groups - the top-level groups to collect for

valueSelector - a group selector to determine which values to collect per-group

Method Detail

getGroups

public java.util.List<DistinctValuesCollector.GroupCount<T,R>> getGroups()

Returns all unique values for each top N group.

Returns:

all unique values for each top N group