Package opennlp.tools.util.featuregen

Class DictionaryFeatureGenerator

java.lang.Object

opennlp.tools.util.featuregen.DictionaryFeatureGenerator

All Implemented Interfaces:

opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

@ThreadSafe
public class DictionaryFeatureGenerator
extends Object
implements opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

The DictionaryFeatureGenerator uses a DictionaryNameFinder to generate features for detected names based on the InSpanGenerator.

Thread safety: in normal use the underlying InSpanGenerator is configured once at construction time and never replaced, after which createFeatures(java.util.List<java.lang.String>, java.lang.String[], int, java.lang.String[]) is safe to call from many threads concurrently (it delegates to a thread-safe InSpanGenerator). The isg field is volatile to give safe publication for both that one-shot constructor write and any later setDictionary call.

setDictionary replaces the in-flight dictionary; it is intended for setup time and is not for hot-path use while createFeatures(java.util.List<java.lang.String>, java.lang.String[], int, java.lang.String[]) is running on other threads — it does not coordinate with in-flight reads beyond the volatile publish, so a caller racing dictionary replacement against feature generation may observe either the old or the new dictionary's features for any given call.

See Also:

• Dictionary
• DictionaryNameFinder
• InSpanGenerator

Constructor Summary

Constructors

Constructor	Description
DictionaryFeatureGenerator(String prefix, Dictionary dict)	Initializes a DictionaryFeatureGenerator with the specified parameters.
DictionaryFeatureGenerator(Dictionary dict)	Initializes a DictionaryFeatureGenerator with the specified Dictionary.

Method Summary

Modifier and Type	Method	Description
void	createFeatures(List<String> features, String[] tokens, int index, String[] previousOutcomes)
void	setDictionary(String name, Dictionary dict)
void	setDictionary(Dictionary dict)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

clearAdaptiveData, updateAdaptiveData

Constructor Details

DictionaryFeatureGenerator

public DictionaryFeatureGenerator(Dictionary dict)

Initializes a DictionaryFeatureGenerator with the specified Dictionary.

Parameters:

dict - The Dictionary to use. Must not be null.

DictionaryFeatureGenerator

public DictionaryFeatureGenerator(String prefix,
 Dictionary dict)

Initializes a DictionaryFeatureGenerator with the specified parameters.

Parameters:

prefix - The prefix to set. Must not be null but may be empty.

dict - The Dictionary to use. Must not be null.

Method Details

setDictionary

public void setDictionary(Dictionary dict)

setDictionary

public void setDictionary(String name,
 Dictionary dict)

createFeatures

public void createFeatures(List<String> features,
 String[] tokens,
 int index,
 String[] previousOutcomes)

Specified by:

createFeatures in interface opennlp.tools.util.featuregen.AdaptiveFeatureGenerator