Class AllGroupsCollector<T>

  • All Implemented Interfaces:
    Collector, LeafCollector

    public class AllGroupsCollector<T>
    extends SimpleCollector
    A collector that collects all groups that match the query. Only the group value is collected, and the order is undefined. This collector does not determine the most relevant document of a group.
    • Field Detail

      • groups

        private final java.util.Set<T> groups
    • Constructor Detail

      • AllGroupsCollector

        public AllGroupsCollector​(GroupSelector<T> groupSelector)
        Create a new AllGroupsCollector
        Parameters:
        groupSelector - the GroupSelector to determine groups
    • Method Detail

      • getGroupCount

        public int getGroupCount()
        Returns the total number of groups for the executed search. This is a convenience method. The following code snippet has the same effect:
        getGroups().size()
        Returns:
        The total number of groups for the executed search
      • getGroups

        public java.util.Collection<T> getGroups()
        Returns the group values

        This is an unordered collections of group values.

        Returns:
        the group values
      • collect

        public void collect​(int doc)
                     throws java.io.IOException
        Description copied from interface: LeafCollector
        Called once for every document matching a query, with the unbased document number.

        Note: The collection of the current segment can be terminated by throwing a CollectionTerminatedException. In this case, the last docs of the current LeafReaderContext will be skipped and IndexSearcher will swallow the exception and continue collection with the next leaf.

        Note: This is called in an inner search loop. For good search performance, implementations of this method should not call IndexSearcher.doc(int) or IndexReader.document(int) on every hit. Doing so can slow searches by an order of magnitude or more.

        Specified by:
        collect in interface LeafCollector
        Specified by:
        collect in class SimpleCollector
        Throws:
        java.io.IOException
      • scoreMode

        public ScoreMode scoreMode()
        Description copied from interface: Collector
        Indicates what features are required from the scorer.