Package opennlp.tools.chunker

Class ThreadSafeChunkerME

java.lang.Object

opennlp.tools.chunker.ThreadSafeChunkerME

All Implemented Interfaces:

AutoCloseable, Chunker, Probabilistic

@ThreadSafe
public class ThreadSafeChunkerME
extends Object
implements Chunker, Probabilistic, AutoCloseable

A thread-safe version of the ChunkerME. Using it is completely transparent. You can use it in a single-threaded context as well, it only incurs a minimal overhead.

Note:
This implementation uses a ThreadLocal. Although the implementation is lightweight because the model is not duplicated, if you have many long-running threads, you may run into memory problems.

Be careful when using this in a Jakarta EE application, for example.

The user is responsible for clearing the ThreadLocal via calling close().

See Also:

• Chunker
• ChunkerME
• Probabilistic

Constructor Summary

Constructors

Constructor	Description
ThreadSafeChunkerME(ChunkerModel model)	Initializes a ThreadSafeChunkerME with the specified model.

Method Summary

Modifier and Type	Method	Description
String[]	chunk(String[] toks, String[] tags)	Generates chunk tags for the given sequence returning the result in an array.
Span[]	chunkAsSpans(String[] toks, String[] tags)	Generates tagged chunk spans for the given sequence returning the result in a span array.
void	close()
double[]	probs()	Retrieves the probabilities of the last decoded sequence.
Sequence[]	topKSequences(String[] sentence, String[] tags)	Computes the top k chunk sequences for the specified sentence with the specified pos-tags.
Sequence[]	topKSequences(String[] sentence, String[] tags, double minSequenceScore)	Computes the top k chunk sequences for the specified sentence with the specified pos-tags.

Methods inherited from class java.lang.Object

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

Constructor Details

ThreadSafeChunkerME

public ThreadSafeChunkerME(ChunkerModel model)

Initializes a ThreadSafeChunkerME with the specified model.

Parameters:

model - A valid ChunkerModel.

Method Details

chunk

public String[] chunk(String[] toks,
 String[] tags)

Description copied from interface: Chunker

Generates chunk tags for the given sequence returning the result in an array.

Specified by:

chunk in interface Chunker

Parameters:

toks - an array of the tokens or words of the sequence.

tags - an array of the pos tags of the sequence.

Returns:

an array of chunk tags for each token in the sequence.

chunkAsSpans

public Span[] chunkAsSpans(String[] toks,
 String[] tags)

Description copied from interface: Chunker

Generates tagged chunk spans for the given sequence returning the result in a span array.

Specified by:

chunkAsSpans in interface Chunker

Parameters:

toks - an array of the tokens or words of the sequence.

tags - an array of the pos tags of the sequence.

Returns:

an array of spans with chunk tags for each chunk in the sequence.

topKSequences

public Sequence[] topKSequences(String[] sentence,
 String[] tags)

Description copied from interface: Chunker

Computes the top k chunk sequences for the specified sentence with the specified pos-tags.

Specified by:

topKSequences in interface Chunker

Parameters:

sentence - The tokens of the sentence.

tags - The pos-tags for the specified sentence.

Returns:

the top k chunk sequences for the specified sentence.

topKSequences

public Sequence[] topKSequences(String[] sentence,
 String[] tags,
 double minSequenceScore)

Description copied from interface: Chunker

Computes the top k chunk sequences for the specified sentence with the specified pos-tags.

Specified by:

topKSequences in interface Chunker

Parameters:

sentence - The tokens of the sentence.

tags - The pos-tags for the specified sentence.

minSequenceScore - A lower bound on the score of a returned sequence.

Returns:

the top k chunk sequences for the specified sentence.

close

public void close()

Specified by:

close in interface AutoCloseable

probs

public double[] probs()

Description copied from interface: Probabilistic

Retrieves the probabilities of the last decoded sequence.

Specified by:

probs in interface Probabilistic

Returns:

An array with the same number of probabilities as tokens were sent to the computational method when it was last called.