Package opennlp.tools.sentdetect

Class SentenceDetectorME

java.lang.Object

opennlp.tools.sentdetect.SentenceDetectorME

All Implemented Interfaces:

opennlp.tools.ml.Probabilistic, opennlp.tools.sentdetect.SentenceDetector

@ThreadSafe
public class SentenceDetectorME
extends Object
implements opennlp.tools.sentdetect.SentenceDetector, opennlp.tools.ml.Probabilistic

A sentence detector for splitting up raw text into sentences.

A maximum entropy model is used to evaluate end-of-sentence characters in a string to determine if they signify the end of a sentence.

A sentence detector instance is thread-safe. One instance can be shared across multiple threads to save memory.

Note: In container environments with classloader isolation (e.g. Jakarta EE), ensure instances do not outlive the application's lifecycle, as underlying components use ThreadLocal state that may pin the classloader.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	NO_SPLIT	Constant indicates no sentence split.
static final String	SPLIT	Constant indicates a sentence split.

Constructor Summary

Constructors

Constructor	Description
SentenceDetectorME(String language)	Initializes the sentence detector by downloading a default model.
SentenceDetectorME(SentenceModel model)	Initializes the current instance.
SentenceDetectorME(SentenceModel model, Dictionary abbDict)	Instantiates a SentenceDetectorME with an existing SentenceModel.
SentenceDetectorME(SentenceModel model, Factory factory)	Deprecated. Use a SentenceDetectorFactory to extend SentenceDetector functionality.

Method Summary

Modifier and Type	Method	Description
void	clearThreadLocalState()	Removes thread-local state to prevent classloader leaks in container environments.
double[]	getSentenceProbabilities()	Deprecated, for removal: This API element is subject to removal in a future version. Use probs() instead.
double[]	probs()	The sequence was determined based on the previous call to sentDetect(CharSequence).
String[]	sentDetect(CharSequence s)	Detects sentences in given input CharSequence..
opennlp.tools.util.Span[]	sentPosDetect(CharSequence s)	Detects the position of the first words of sentences in a CharSequence.
static SentenceModel	train(String languageCode, opennlp.tools.util.ObjectStream<opennlp.tools.sentdetect.SentenceSample> samples, SentenceDetectorFactory sdFactory, opennlp.tools.util.TrainingParameters mlParams)	Starts a training of a SentenceModel with the given parameters.

Methods inherited from class java.lang.Object

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

Field Details

SPLIT

public static final String SPLIT

Constant indicates a sentence split.

See Also:

• Constant Field Values

NO_SPLIT

public static final String NO_SPLIT

Constant indicates no sentence split.

See Also:

• Constant Field Values

Constructor Details

SentenceDetectorME

public SentenceDetectorME(String language)
                   throws IOException

Initializes the sentence detector by downloading a default model.

Parameters:

language - The language of the sentence detector.

Throws:

IOException - Thrown if the model cannot be downloaded or saved.

SentenceDetectorME

public SentenceDetectorME(SentenceModel model)

Initializes the current instance.

Parameters:

model - the SentenceModel

SentenceDetectorME

public SentenceDetectorME(SentenceModel model,
 Dictionary abbDict)

Instantiates a SentenceDetectorME with an existing SentenceModel.

Parameters:

model - The SentenceModel to be used.

abbDict - The Dictionary to be used. It must fit the language of the model.

SentenceDetectorME

@Deprecated
public SentenceDetectorME(SentenceModel model,
 Factory factory)

Deprecated.

Use a SentenceDetectorFactory to extend SentenceDetector functionality.

Method Details

sentDetect

public String[] sentDetect(CharSequence s)

Detects sentences in given input CharSequence..

Specified by:

sentDetect in interface opennlp.tools.sentdetect.SentenceDetector

Parameters:

s - The CharSequence. to be processed.

Returns:

A string array containing individual sentences as elements.

sentPosDetect

public opennlp.tools.util.Span[] sentPosDetect(CharSequence s)

Detects the position of the first words of sentences in a CharSequence.

Specified by:

sentPosDetect in interface opennlp.tools.sentdetect.SentenceDetector

Parameters:

s - The CharSequence to be processed.

Returns:

An span array containing the positions of the end index of every sentence.

probs

public double[] probs()

The sequence was determined based on the previous call to sentDetect(CharSequence).

Specified by:

probs in interface opennlp.tools.ml.Probabilistic

Returns:

an array with the same number of probabilities as for the last sentDetect(CharSequence) call; if not applicable, an empty array

clearThreadLocalState

public void clearThreadLocalState()

Removes thread-local state to prevent classloader leaks in container environments. Call when the thread is returned to a pool or the sentence detector is no longer needed.

getSentenceProbabilities

@Deprecated(forRemoval=true,
            since="2.5.5")
public double[] getSentenceProbabilities()

Deprecated, for removal: This API element is subject to removal in a future version.

Use probs() instead.

Returns:

The probability for each sentence returned for the most recent call to sentDetect(CharSequence); if not applicable, an empty array

train

public static SentenceModel train(String languageCode,
 opennlp.tools.util.ObjectStream<opennlp.tools.sentdetect.SentenceSample> samples,
 SentenceDetectorFactory sdFactory,
 opennlp.tools.util.TrainingParameters mlParams)
                           throws IOException

Starts a training of a SentenceModel with the given parameters.

Parameters:

languageCode - The ISO language code to train the model. Must not be null.

samples - The ObjectStream of SentenceSample used as input for training.

sdFactory - The SentenceDetectorFactory for creating related objects as defined via mlParams.

mlParams - The TrainingParameters for the context of the training process.

Returns:

A valid, trained SentenceModel instance.

Throws:

IOException - Thrown if IO errors occurred.