# All Packages

Package Summary
Package
Description
org.apache.lucene.analysis
Text analysis.
org.apache.lucene.analysis.standard
Fast, general-purpose grammar-based tokenizer `StandardTokenizer` implements the Word Break rules from the Unicode Text Segmentation algorithm, as specified in Unicode Standard Annex #29.
org.apache.lucene.analysis.tokenattributes
General-purpose attributes for text analysis.
org.apache.lucene.codecs
Codecs API: API for customization of the encoding and structure of the index.
org.apache.lucene.codecs.compressing
Compressing helper classes.
org.apache.lucene.codecs.hnsw
HNSW vector helper classes.
org.apache.lucene.codecs.lucene100
Lucene 10.0 file format.
org.apache.lucene.codecs.lucene90
Lucene 9.0 file format.
org.apache.lucene.codecs.lucene90.blocktree
BlockTree terms dictionary.
org.apache.lucene.codecs.lucene90.compressing
Lucene 9.0 compressing format.
org.apache.lucene.codecs.lucene912
Lucene 9.12 file format.
org.apache.lucene.codecs.lucene94
Lucene 9.4 file format.
org.apache.lucene.codecs.lucene95
Lucene 9.5 file format.
org.apache.lucene.codecs.lucene99
Lucene 9.9 file format.
org.apache.lucene.codecs.perfield
Postings format that can delegate to different formats per-field.
org.apache.lucene.document
The logical representation of a `Document` for indexing and searching.
org.apache.lucene.geo
Geospatial Utility Implementations for Lucene Core
org.apache.lucene.index
Code to maintain and access indices.
org.apache.lucene.internal.hppc
Internal copy of a subset of classes from the HPPC library.
org.apache.lucene.internal.tests
Internal bridges to package-private internals, for use by the lucene test framework only.
org.apache.lucene.internal.vectorization
Internal implementations to support SIMD vectorization.
org.apache.lucene.search
Code to search indices.
org.apache.lucene.search.comparators
Comparators, used to compare hits so as to determine their sort order when collecting the top results with `TopFieldCollector`.
org.apache.lucene.search.knn
Classes related to vector search: knn and vector fields.
org.apache.lucene.search.similarities
This package contains the various ranking models that can be used in Lucene.
org.apache.lucene.store
Binary i/o API, used for all index data.
org.apache.lucene.util
Some utility classes.
org.apache.lucene.util.automaton
Finite-state automaton for regular expressions.
org.apache.lucene.util.bkd
Block KD-tree, implementing the generic spatial data structure described in this paper.
org.apache.lucene.util.compress
Compression utilities.
org.apache.lucene.util.fst
Finite state transducers
org.apache.lucene.util.graph
Utility classes for working with token streams as graphs.
org.apache.lucene.util.hnsw
Navigable Small-World graph, nominally Hierarchical but currently only has a single layer.
org.apache.lucene.util.mutable
Comparable object wrappers
org.apache.lucene.util.packed
Packed integer arrays and streams.
org.apache.lucene.util.quantization
Provides quantization methods for scaling vector values to smaller data types and possibly fewer dimensions