## org.apache.lucene.search.grouping
Class AbstractSecondPassGroupingCollector<GROUP_VALUE_TYPE>

    java.lang.Object
      org.apache.lucene.search.Collector
          org.apache.lucene.search.grouping.AbstractSecondPassGroupingCollector<GROUP_VALUE_TYPE>

Direct Known Subclasses:
  TermSecondPassGroupingCollector

    public abstract class AbstractSecondPassGroupingCollector<GROUP_VALUE_TYPE>

extends org.apache.lucene.search.Collector

SecondPassGroupingCollector is the second of two passes necessary to collect grouped docs. This pass gathers the top N documents per top group computed from the first pass. Concrete subclasses define what a group is and how it is internally collected.

See `org.apache.lucene.search.grouping` for more details including a full code example.

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

Nested Class Summary
`class` `AbstractSecondPassGroupingCollector.SearchGroupDocs<GROUP_VALUE_TYPE>`

Field Summary
`protected AbstractSecondPassGroupingCollector.SearchGroupDocs<GROUP_VALUE_TYPE>[]` `groupDocs`
`protected Map<GROUP_VALUE_TYPE,AbstractSecondPassGroupingCollector.SearchGroupDocs<GROUP_VALUE_TYPE>>` `groupMap`

Constructor Summary
`AbstractSecondPassGroupingCollector(Collection<SearchGroup<GROUP_VALUE_TYPE>> groups, org.apache.lucene.search.Sort groupSort, org.apache.lucene.search.Sort withinGroupSort, int maxDocsPerGroup, boolean getScores, boolean getMaxScores, boolean fillSortFields)`

Method Summary
`boolean` `acceptsDocsOutOfOrder()`
`void` `collect(int doc)`
`TopGroups<GROUP_VALUE_TYPE>` `getTopGroups(int withinGroupOffset)`
`protected abstract AbstractSecondPassGroupingCollector.SearchGroupDocs<GROUP_VALUE_TYPE>` `retrieveGroup(int doc)` Returns the group the specified doc belongs to or `null` if no group could be retrieved.
`void` `setNextReader(org.apache.lucene.index.IndexReader reader, int docBase)`
`void` `setScorer(org.apache.lucene.search.Scorer scorer)`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### groupMap

    protected final Map<GROUP_VALUE_TYPE,AbstractSecondPassGroupingCollector.SearchGroupDocs<GROUP_VALUE_TYPE>> groupMap

### groupDocs

    protected AbstractSecondPassGroupingCollector.SearchGroupDocs<GROUP_VALUE_TYPE>[] groupDocs

Constructor Detail

### AbstractSecondPassGroupingCollector

    public AbstractSecondPassGroupingCollector(Collection<SearchGroup<GROUP_VALUE_TYPE>> groups,
                                               org.apache.lucene.search.Sort groupSort,
                                               org.apache.lucene.search.Sort withinGroupSort,
                                               int maxDocsPerGroup,
                                               boolean getScores,
                                               boolean getMaxScores,
                                               boolean fillSortFields)
                                        throws IOException

Throws:
  `IOException`

Method Detail

### setScorer

    public void setScorer(org.apache.lucene.search.Scorer scorer)
                   throws IOException

  Specified by:
    `setScorer` in class `org.apache.lucene.search.Collector`
  Throws:
    `IOException`

### collect

    public void collect(int doc)
                 throws IOException

  Specified by:
    `collect` in class `org.apache.lucene.search.Collector`
  Throws:
    `IOException`

### retrieveGroup

    protected abstract AbstractSecondPassGroupingCollector.SearchGroupDocs<GROUP_VALUE_TYPE> retrieveGroup(int doc)
                                                                                                    throws IOException

  Returns the group the specified doc belongs to or `null` if no group could be retrieved.

  Parameters:
    `doc` - The specified doc
  Returns:
    the group the specified doc belongs to or `null` if no group could be retrieved
  Throws:
    `IOException` - If an I/O related error occurred

### setNextReader

    public void setNextReader(org.apache.lucene.index.IndexReader reader,
                              int docBase)
                       throws IOException

  Specified by:
    `setNextReader` in class `org.apache.lucene.search.Collector`
  Throws:
    `IOException`

### acceptsDocsOutOfOrder

    public boolean acceptsDocsOutOfOrder()

  Specified by:
    `acceptsDocsOutOfOrder` in class `org.apache.lucene.search.Collector`

### getTopGroups

    public TopGroups<GROUP_VALUE_TYPE> getTopGroups(int withinGroupOffset)