org.apache.lucene.search.grouping

Class AbstractDistinctValuesCollector<GC extends AbstractDistinctValuesCollector.GroupCount<?>>

java.lang.Object

org.apache.lucene.search.SimpleCollector

org.apache.lucene.search.grouping.AbstractDistinctValuesCollector<GC>

All Implemented Interfaces:

Collector, LeafCollector

Direct Known Subclasses:

FunctionDistinctValuesCollector, TermDistinctValuesCollector

public abstract class AbstractDistinctValuesCollector<GC extends AbstractDistinctValuesCollector.GroupCount<?>>
extends SimpleCollector

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	AbstractDistinctValuesCollector.GroupCount<GROUP_VALUE_TYPE> Returned by getGroups(), representing the value and set of distinct values for the group.

Constructor Summary

Constructors

Constructor and Description
AbstractDistinctValuesCollector()

Method Summary

Modifier and Type	Method and Description
abstract List<GC>	getGroups() Returns all unique values for each top N group.
boolean	needsScores() Indicates if document scores are needed by this collector.

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

AbstractDistinctValuesCollector

public AbstractDistinctValuesCollector()

Method Detail

getGroups

public abstract List<GC> getGroups()

Returns all unique values for each top N group.

Returns:

all unique values for each top N group

needsScores

public boolean needsScores()

Description copied from interface: Collector

Indicates if document scores are needed by this collector.

Returns:

true if scores are needed.