# Package org.apache.lucene.facet.taxonomy

Taxonomy of Categories

See: Description

Interface Summary
Interface | Description
--- | ---
TaxonomyWriter | TaxonomyWriter is the interface which the faceted-search library uses to dynamically build the taxonomy at indexing time.

Class Summary
Class | Description
--- | ---
CategoryPath | Holds a sequence of string components, specifying the hierarchical name of a category.
TaxonomyReader | TaxonomyReader is the read-only interface with which the faceted-search library uses the taxonomy during search time.

## Package org.apache.lucene.facet.taxonomy Description

# Taxonomy of Categories

Facets are defined using a hierarchy of categories, known as a Taxonomy.
For example, in a book store application, a Taxonomy could have the following hierarchy:

- Author

- Mark Twain
- J. K. Rowling

- Date

- 2010
- 2009

The Taxonomy translates category-paths into category-ordinal and vice versa.