org.apache.lucene.search.grouping

Class DistinctValuesCollector<T>

java.lang.Object

org.apache.lucene.search.SimpleCollector

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

All Implemented Interfaces:

Collector, LeafCollector

Direct Known Subclasses:

FunctionDistinctValuesCollector, TermDistinctValuesCollector

public abstract class DistinctValuesCollector<T>
extends SimpleCollector

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

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes

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

Constructor Summary

Constructors

Constructor and Description
DistinctValuesCollector()

Method Summary

Modifier and Type	Method and Description
abstract List<DistinctValuesCollector.GroupCount<T>>	getGroups() Returns all unique values for each top N group.
boolean	needsScores()

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

collect, doSetNextReader, getLeafCollector, setScorer

Methods inherited from class java.lang.Object

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

Constructor Detail

DistinctValuesCollector

public DistinctValuesCollector()

Method Detail

getGroups

public abstract List<DistinctValuesCollector.GroupCount<T>> getGroups()

Returns all unique values for each top N group.

Returns:

all unique values for each top N group

needsScores

public boolean needsScores()