Class ChunkerAnnotator

java.lang.Object

opennlp.tools.chunker.ChunkerAnnotator

All Implemented Interfaces:

opennlp.tools.document.DocumentAnnotator

public final class ChunkerAnnotator
extends Object
implements opennlp.tools.document.DocumentAnnotator

Adapts a Chunker to the document pipeline: reads Layers.SENTENCES, Layers.TOKENS, and Layers.POS_TAGS and provides CHUNKS, one annotation per phrase chunk carrying the chunk type, for example NP or VP, on the span from its first to its last token.

Each sentence is chunked separately with its tokens and tags as one sequence, the way the chunker contract expects its input. A chunker's spans index tokens within the sentence; the adapter maps them onto the token spans, which already refer to the original text, so a chunk covers exactly the text of its tokens. Chunks are emitted in text order.

The adapter holds no per-call state; it is as thread-safe as the chunker it wraps.

Since:

3.0.0

Field Summary

Fields

Modifier and Type	Field	Description
static final opennlp.tools.document.LayerKey<String>	CHUNKS	Phrase chunks; each annotation covers one chunk and carries its type, ordered by text position.

Constructor Summary

Constructors

Constructor	Description
ChunkerAnnotator(opennlp.tools.chunker.Chunker chunker)	Initializes the adapter.

Method Summary

Modifier and Type	Method	Description
opennlp.tools.document.Document	annotate(opennlp.tools.document.Document document)	Chunks the document sentence by sentence and adds the CHUNKS layer.
Set<opennlp.tools.document.LayerKey<?>>	provides()
Set<opennlp.tools.document.LayerKey<?>>	requires()
String	toString()	Returns the adapter's simple class name, which names it in pipeline validation messages.

Methods inherited from class Object

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

Field Details

CHUNKS

public static final opennlp.tools.document.LayerKey<String> CHUNKS

Phrase chunks; each annotation covers one chunk and carries its type, ordered by text position.

Constructor Details

ChunkerAnnotator

public ChunkerAnnotator(opennlp.tools.chunker.Chunker chunker)

Initializes the adapter.

Parameters:

chunker - The chunker to delegate to. Must not be null.

Throws:

IllegalArgumentException - Thrown if chunker is null.

Method Details

annotate

public opennlp.tools.document.Document annotate(opennlp.tools.document.Document document)

Chunks the document sentence by sentence and adds the CHUNKS layer.

The required layers must be present, but they may be empty: a document without sentences or tokens yields a present-but-empty chunk layer. The token and tag layers must be aligned one to one.

Specified by:

annotate in interface opennlp.tools.document.DocumentAnnotator

Parameters:

document - The document to annotate. Must not be null and must carry the Layers.SENTENCES, Layers.TOKENS, and Layers.POS_TAGS layers, with every token lying inside a sentence.

Returns:

A new Document with the CHUNKS layer added. Never null.

Throws:

IllegalArgumentException - Thrown if document is null, a required layer is absent, the token and tag layers differ in size, a token lies outside every sentence, or the chunker returns a span outside the sentence, an empty span, or a span without a type.

requires

public Set<opennlp.tools.document.LayerKey<?>> requires()

Specified by:

requires in interface opennlp.tools.document.DocumentAnnotator

provides

public Set<opennlp.tools.document.LayerKey<?>> provides()

Specified by:

provides in interface opennlp.tools.document.DocumentAnnotator

toString

public String toString()

Returns the adapter's simple class name, which names it in pipeline validation messages.

Overrides:

toString in class Object

Returns:

the adapter's simple class name, which names it in pipeline validation messages