Package opennlp.tools.util.featuregen

Class CachedFeatureGenerator

java.lang.Object

opennlp.tools.util.featuregen.CachedFeatureGenerator

All Implemented Interfaces:

opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

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

Caches features of the aggregated generators.

The cache is maintained per-thread via ThreadLocal, making this class safe for concurrent use from multiple threads. Each thread gets its own independent cache that is cleared when a new sentence (token array) is encountered.

Cache key is reference identity, not content. The "is this still the same sentence?" check uses tokens == state.prevTokens; passing a freshly allocated String[] with the same contents is treated as a new sentence and triggers a cache miss + clear. Reuse the same tokens array across calls when you need the cache to hit.

Note: In container environments with classloader isolation (e.g. Jakarta EE), ThreadLocal state may pin the classloader. Ensure instances do not outlive the application's lifecycle, or call ThreadLocal.remove() on pooled threads.

See Also:

• Cache

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DISABLE_CACHE_PROPERTY	System property to disable the feature cache globally.

Constructor Summary

Constructors

Constructor	Description
CachedFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator generator)
CachedFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator... generators)	Deprecated. Use CachedFeatureGenerator(AdaptiveFeatureGenerator) instead.

Method Summary

Modifier and Type	Method	Description
void	clearAdaptiveData()
void	createFeatures(List<String> features, String[] tokens, int index, String[] previousOutcomes)
opennlp.tools.util.featuregen.AdaptiveFeatureGenerator	getCachedFeatureGenerator()
long	getNumberOfCacheHits()	Deprecated. Cache statistics are no longer tracked.
long	getNumberOfCacheMisses()	Deprecated. Cache statistics are no longer tracked.
void	updateAdaptiveData(String[] tokens, String[] outcomes)

Methods inherited from class java.lang.Object

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

Field Details

DISABLE_CACHE_PROPERTY

public static final String DISABLE_CACHE_PROPERTY

System property to disable the feature cache globally. Set to "true" to bypass caching (useful for benchmarking).

See Also:

• Constant Field Values

Constructor Details

CachedFeatureGenerator

@Deprecated
public CachedFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator... generators)

Deprecated.

Use CachedFeatureGenerator(AdaptiveFeatureGenerator) instead.

CachedFeatureGenerator

public CachedFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator generator)

Method Details

createFeatures

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

Specified by:

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

updateAdaptiveData

public void updateAdaptiveData(String[] tokens,
 String[] outcomes)

Specified by:

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

clearAdaptiveData

public void clearAdaptiveData()

Specified by:

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

getNumberOfCacheHits

@Deprecated(since="3.0.0")
public long getNumberOfCacheHits()

Deprecated.

Cache statistics are no longer tracked.

Returns:

Retrieves the number of cache hits for the current thread.

getNumberOfCacheMisses

@Deprecated(since="3.0.0")
public long getNumberOfCacheMisses()

Deprecated.

Cache statistics are no longer tracked.

Returns:

Retrieves the number of cache misses for the current thread.

getCachedFeatureGenerator

public opennlp.tools.util.featuregen.AdaptiveFeatureGenerator getCachedFeatureGenerator()