opennlp.tools.util.featuregen (Apache OpenNLP Tools 1.9.5 API)
Date: 2026-06-18

# Package opennlp.tools.util.featuregen

This package contains classes for generating sequence features.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  AdaptiveFeatureGenerator | An interface for generating features for name entity identification and for updating document level contexts.
  ArtifactToSerializerMapper | Deprecated
  FeatureGeneratorResourceProvider | The `FeatureGeneratorResourceProvider` provides access to the resources provided in the model.

- Class Summary
  Class | Description
  --- | ---
  AdditionalContextFeatureGenerator | The `AdditionalContextFeatureGenerator` generates the context from the passed in additional context.
  AggregatedFeatureGenerator | The `AggregatedFeatureGenerator` aggregates a set of `AdaptiveFeatureGenerator`s and calls them to generate the features.
  AggregatedFeatureGeneratorFactory |
  BigramNameFeatureGenerator |
  BigramNameFeatureGeneratorFactory |
  BrownBigramFeatureGenerator | Generates Brown cluster features for token bigrams.
  BrownCluster | Class to load a Brown cluster document: word\tword_class\tprob http://metaoptimize.com/projects/wordreprs/ The file containing the clustering lexicon has to be passed as the value of the dict attribute of each BrownCluster feature generator.
  BrownCluster.BrownClusterSerializer |
  BrownClusterBigramFeatureGeneratorFactory | Generates Brown clustering features for token bigrams.
  BrownClusterTokenClassFeatureGeneratorFactory | Generates Brown clustering features for token classes.
  BrownClusterTokenFeatureGeneratorFactory | Generates Brown clustering features for current token.
  BrownTokenClasses | Obtain the paths listed in the pathLengths array from the Brown class.
  BrownTokenClassFeatureGenerator | Generates Brown cluster features for current token and token class.
  BrownTokenFeatureGenerator | Generates Brown cluster features for current token.
  CachedFeatureGenerator | Caches features of the aggregated `AdaptiveFeatureGenerator`s.
  CachedFeatureGeneratorFactory |
  CharacterNgramFeatureGenerator | The `CharacterNgramFeatureGenerator` uses character ngrams to generate features about each token.
  CharacterNgramFeatureGeneratorFactory |
  CustomFeatureGenerator | Deprecated
  DefinitionFeatureGeneratorFactory |
  DictionaryFeatureGenerator | The `DictionaryFeatureGenerator` uses the `DictionaryNameFinder` to generated features for detected names based on the `InSpanGenerator`.
  DictionaryFeatureGeneratorFactory |
  DocumentBeginFeatureGenerator |
  DocumentBeginFeatureGeneratorFactory |
  FeatureGeneratorUtil | This class provide common utilities for feature generation.
  GeneratorFactory | Creates a set of feature generators based on a provided XML descriptor.
  GeneratorFactory.AbstractXmlFeatureGeneratorFactory |
  InSpanGenerator | Generates features if the tokens are recognized by the provided `TokenNameFinder`.
  OutcomePriorFeatureGenerator | The definition feature maps the underlying distribution of outcomes.
  PosTaggerFeatureGenerator |
  PosTaggerFeatureGeneratorFactory |
  POSTaggerNameFeatureGenerator | Adds the token POS Tag as feature.
  POSTaggerNameFeatureGeneratorFactory |
  PrefixFeatureGenerator |
  PrefixFeatureGeneratorFactory |
  PreviousMapFeatureGenerator | This `AdaptiveFeatureGenerator` generates features indicating the outcome associated with a previously occuring word.
  PreviousMapFeatureGeneratorFactory |
  PreviousTwoMapFeatureGenerator | This `AdaptiveFeatureGenerator` generates features indicating the outcome associated with two previously occuring words.
  SentenceFeatureGenerator | This feature generator creates sentence begin and end features.
  SentenceFeatureGeneratorFactory |
  StringPattern | Recognizes predefined patterns in strings.
  SuffixFeatureGenerator |
  SuffixFeatureGeneratorFactory |
  TokenClassFeatureGenerator | Generates features for different for the class of the token.
  TokenClassFeatureGeneratorFactory |
  TokenFeatureGenerator | Generates a feature which contains the token itself.
  TokenFeatureGeneratorFactory |
  TokenPatternFeatureGenerator | Partitions tokens into sub-tokens based on character classes and generates class features for each of the sub-tokens and combinations of those sub-tokens.
  TokenPatternFeatureGeneratorFactory |
  TrigramNameFeatureGenerator | Adds trigram features based on tokens and token classes.
  TrigramNameFeatureGeneratorFactory |
  WindowFeatureGenerator | Generates previous and next features for a given `AdaptiveFeatureGenerator`.
  WindowFeatureGeneratorFactory |
  WordClusterDictionary |
  WordClusterDictionary.WordClusterDictionarySerializer |
  WordClusterFeatureGenerator |
  WordClusterFeatureGeneratorFactory | Defines a word cluster generator factory; it reads an element containing 'w2vwordcluster' as a tag name; these clusters are typically produced by word2vec or clark pos induction systems.

## Package opennlp.tools.util.featuregen Description

This package contains classes for generating sequence features.

Copyright © 2026 The Apache Software Foundation. All rights reserved.