Class Facets

java.lang.Object
org.apache.lucene.facet.Facets
Direct Known Subclasses:
ConcurrentSortedSetDocValuesFacetCounts, FacetCountsWithFilterQuery, LongValueFacetCounts, MultiFacets, SortedSetDocValuesFacetCounts, StringValueFacetCounts, TaxonomyFacets

public abstract class Facets extends Object
Common base class for all facets implementations.
WARNING: This API is experimental and might change in incompatible ways in the next release.
  • Constructor Summary

    Constructors
    Constructor
    Description
    Default constructor.
  • Method Summary

    Modifier and Type
    Method
    Description
    abstract FacetResult
    getAllChildren(String dim, String... path)
    Returns all child labels with non-zero counts under the specified path.
    abstract List<FacetResult>
    getAllDims(int topN)
    Returns topN labels for any dimension that had hits, sorted by the number of hits that dimension matched; this is used for "sparse" faceting, where many different dimensions were indexed, for example depending on the type of document.
    abstract Number
    Return the count or value for a specific path.
    abstract FacetResult
    getTopChildren(int topN, String dim, String... path)
    Returns the topN child labels under the specified path.
    getTopDims(int topNDims, int topNChildren)
    Returns labels for topN dimensions and their topNChildren sorted by the number of hits/aggregated values that dimension matched.
    protected static void
    validateTopN(int topN)
    This helper method checks if topN is valid for getTopChildren and getAllDims.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • Facets

      public Facets()
      Default constructor.
  • Method Details

    • getAllChildren

      public abstract FacetResult getAllChildren(String dim, String... path) throws IOException
      Returns all child labels with non-zero counts under the specified path. Users should make no assumptions about ordering of the children. Returns null if the specified path doesn't exist or if this dimension was never seen.
      Throws:
      IOException
    • getTopChildren

      public abstract FacetResult getTopChildren(int topN, String dim, String... path) throws IOException
      Returns the topN child labels under the specified path. Returns null if the specified path doesn't exist or if this dimension was never seen.
      Throws:
      IOException
    • getSpecificValue

      public abstract Number getSpecificValue(String dim, String... path) throws IOException
      Return the count or value for a specific path. Returns -1 if this path doesn't exist, else the count.
      Throws:
      IOException
    • getAllDims

      public abstract List<FacetResult> getAllDims(int topN) throws IOException
      Returns topN labels for any dimension that had hits, sorted by the number of hits that dimension matched; this is used for "sparse" faceting, where many different dimensions were indexed, for example depending on the type of document.
      Throws:
      IOException
    • getTopDims

      public List<FacetResult> getTopDims(int topNDims, int topNChildren) throws IOException
      Returns labels for topN dimensions and their topNChildren sorted by the number of hits/aggregated values that dimension matched. Results should be the same as calling getAllDims and then only using the first topNDims. Note that dims should be configured as requiring dim counts if using this functionality to ensure accurate counts are available (see: FacetsConfig.setRequireDimCount(String, boolean)).

      Sub-classes may want to override this implementation with a more efficient one if they are able.

      Throws:
      IOException
    • validateTopN

      protected static void validateTopN(int topN)
      This helper method checks if topN is valid for getTopChildren and getAllDims. Throws IllegalArgumentException if topN is invalid.
      WARNING: This API is experimental and might change in incompatible ways in the next release.
      it may not exist in future versions of Lucene