# All Classes and Interfaces

Class
Description
AnalyzingInfixSuggester
Analyzes the input text and then suggests matches based on prefix matches to any tokens in the indexed text.
AnalyzingSuggester
Suggester that first analyzes the surface form, adds the analyzed form to a weighted FST, and then does the same thing at lookup time.
BitsProducer
A producer of `Bits` per segment.
BlendedInfixSuggester
Extension of the AnalyzingInfixSuggester which transforms the weight after search to take into account the position of the searched term into the indexed text.
BlendedInfixSuggester.BlenderType
The different types of blender.
BufferedInputIterator
This wrapper buffers incoming elements.
BytesRefSorter
Collects `BytesRef` and then allows one to iterate over their sorted order.
CombineSuggestion
A suggestion generated by combining one or more original query terms
Completion50PostingsFormat
`CompletionPostingsFormat` for `org.apache.lucene.backward_codecs.lucene50.Lucene50PostingsFormat`.
Completion84PostingsFormat
`CompletionPostingsFormat` for `org.apache.lucene.backward_codecs.lucene84.Lucene84PostingsFormat`.
Completion90PostingsFormat
`CompletionPostingsFormat` for `org.apache.lucene.backward_codecs.lucene90.Lucene90PostingsFormat`.
Completion912PostingsFormat
`CompletionPostingsFormat` for `Lucene912PostingsFormat`
Completion99PostingsFormat
`CompletionPostingsFormat` for `org.apache.lucene.backward_codecs.lucene99.Lucene99PostingsFormat`.
CompletionAnalyzer
Wraps an `Analyzer` to provide additional completion-only tuning (e.g.
CompletionPostingsFormat
A `PostingsFormat` which supports document suggestion based on indexed `SuggestField`s.
CompletionPostingsFormat.FSTLoadMode
An enum that allows to control if suggester FSTs are loaded into memory or read off-heap
CompletionQuery
Abstract `Query` that match documents containing terms with a specified prefix filtered by `BitsProducer`.
CompletionScorer
Expert: Responsible for executing the query against an appropriate suggester and collecting the results via a collector.
CompletionsTermsReader
Holder for suggester and field-level info for a suggest field
CompletionTerms
Wrapped `Terms` used by `SuggestField` and `ContextSuggestField` to access corresponding suggester and their attributes
CompletionTokenStream
A `ConcatenateGraphFilter` but we can set the payload and provide access to config options.
CompletionWeight
Expert: the Weight for CompletionQuery, used to score and explain these queries.
ContextQuery
A `CompletionQuery` that matches documents specified by a wrapped `CompletionQuery` supporting boosting and/or filtering by specified contexts.
ContextSuggestField
`SuggestField` which additionally takes in a set of contexts.
Dictionary
A simple interface representing a Dictionary.
DirectSpellChecker
Simple automaton-based spellchecker.
DirectSpellChecker.ScoreTerm
Holds a spelling correction for internal usage inside `DirectSpellChecker`.
DocumentDictionary
Dictionary with terms, weights, payload (optional) and contexts (optional) information taken from stored/indexed fields in a Lucene index.
DocumentValueSourceDictionary
Dictionary with terms and optionally payload and optionally contexts information taken from stored fields in a Lucene index.
ExternalRefSorter
An implementation of a `BytesRefSorter` that allows appending `BytesRef`s to an `OfflineSorter` and returns a `Closeable` `ExternalRefSorter.ByteSequenceIterator` that iterates over sequences stored on disk.
ExternalRefSorter.ByteSequenceIterator
Iterates over `BytesRef`s in a file, closes the reader when the iterator is exhausted.
FileDictionary
Dictionary represented by a text file.
FreeTextSuggester
Builds an ngram model from the text sent to `FreeTextSuggester.build(org.apache.lucene.search.suggest.InputIterator)` and predicts based on the last grams-1 tokens in the request sent to `FreeTextSuggester.lookup(java.lang.CharSequence, boolean, int)`.
FSTCompletion
Finite state automata based implementation of "autocomplete" functionality.
FSTCompletion.Completion
A single completion for a given key.
FSTCompletionBuilder
Finite state automata based implementation of "autocomplete" functionality.
FSTCompletionLookup
An adapter from `Lookup` API to `FSTCompletion`.
FSTUtil
Exposes a utility method to enumerate all paths intersecting an `Automaton` with an `FST`.
FSTUtil.Path<T>
Holds a pair (automaton, fst) of states and accumulated output in the intersected machine.
FuzzyCompletionQuery
A `CompletionQuery` that match documents containing terms within an edit distance of the specified prefix.
FuzzySuggester
Implements a fuzzy `AnalyzingSuggester`.
HighFrequencyDictionary
HighFrequencyDictionary: terms taken from the given field of a Lucene index, which appear in a number of documents above a given threshold.
InMemorySorter
An `BytesRefSorter` that keeps all the entries in memory.
InputIterator
Interface for enumerating term,weight,payload triples for suggester consumption; currently only `AnalyzingSuggester`, `FuzzySuggester` and `AnalyzingInfixSuggester` support payloads.
InputIterator.InputIteratorWrapper
Wraps a BytesRefIterator as a suggester InputIterator, with all weights set to `1` and carries no payload
JaroWinklerDistance
Similarity measure for short strings such as person names.
LevenshteinDistance
Levenshtein edit distance class.
Lookup
Simple Lookup interface for `CharSequence` suggestions.
Lookup.LookupPriorityQueue
A `PriorityQueue` collecting a fixed size of high priority `Lookup.LookupResult`
Lookup.LookupResult
Result of a lookup.
LuceneDictionary
Lucene Dictionary: terms taken from the given field of a Lucene index.
LuceneLevenshteinDistance
Damerau-Levenshtein (optimal string alignment) implemented in a consistent way as Lucene's FuzzyTermsEnum with the transpositions option enabled.
NGramDistance
N-Gram version of edit distance based on paper by Grzegorz Kondrak, "N-gram similarity and distance".
NRTSuggester
NRTSuggester executes Top N search on a weighted FST specified by a `CompletionScorer`
PlainTextDictionary
Dictionary represented by a text file.
PrefixCompletionQuery
A `CompletionQuery` which takes an `Analyzer` to analyze the prefix of the query term.
RegexCompletionQuery
A `CompletionQuery` which takes a regular expression as the prefix of the query term.
SortedInputIterator
This wrapper buffers incoming elements and makes sure they are sorted based on given comparator.
SpellChecker
Spell Checker class (Main class).
(initially inspired by the David Spencer code).
StringDistance
Interface for string distances.
SuggestField
Field that indexes a string value and a weight as a weighted completion against a named suggester.
SuggestIndexSearcher
Adds document suggest capabilities to IndexSearcher.
SuggestMode
Set of strategies for suggesting related terms
SuggestStopFilter
Like `StopFilter` except it will not remove the last token if that token was not followed by some token separator.
SuggestStopFilterFactory
Factory for `SuggestStopFilter`.
SuggestWord
SuggestWord, used in suggestSimilar method in SpellChecker class.
SuggestWordFrequencyComparator
Frequency first, then score.
SuggestWordQueue
Sorts SuggestWord instances
SuggestWordScoreComparator
Score first, then frequency
TernaryTreeNode
The class creates a TST node.
TopSuggestDocs
`TopDocs` wrapper with an additional CharSequence key per `ScoreDoc`
TopSuggestDocs.SuggestScoreDoc
`ScoreDoc` with an additional CharSequence key
TopSuggestDocsCollector
`Collector` that collects completion and score, along with document id
TSTAutocomplete
Ternary Search Trie implementation.
TSTLookup
Suggest implementation based on a Ternary Search Tree
UnsortedInputIterator
This wrapper buffers the incoming elements and makes sure they are in random order.
WFSTCompletionLookup
Suggester based on a weighted FST: it first traverses the prefix, then walks the n shortest paths to retrieve top-ranked suggestions.
WordBreakSpellChecker
A spell checker whose sole function is to offer suggestions by combining multiple terms into one word and/or breaking terms into multiple words.
WordBreakSpellChecker.BreakSuggestionSortMethod
Determines the order to list word break suggestions