Class POSTaggerAnnotator

java.lang.Object

opennlp.tools.postag.POSTaggerAnnotator

All Implemented Interfaces:

opennlp.tools.document.DocumentAnnotator

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

Adapts a POSTagger to the document pipeline: reads Layers.SENTENCES and Layers.TOKENS and provides Layers.POS_TAGS, one tag annotation per token on the token's span.

Each sentence is tagged separately, the way the tagger contract expects its input, so tagging decisions never cross a sentence boundary. Token spans already refer to the original document text, so only the token sequence handed to the tagger is sliced per sentence; the produced tag layer stays aligned with Layers.TOKENS by position.

Since:

3.0.0

Constructor Summary

Constructors

Constructor	Description
POSTaggerAnnotator(opennlp.tools.postag.POSTagger tagger)	Initializes the adapter.

Method Summary

Modifier and Type	Method	Description
opennlp.tools.document.Document	annotate(opennlp.tools.document.Document document)	Tags the document sentence by sentence and adds the Layers.POS_TAGS 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

Constructor Details

POSTaggerAnnotator

public POSTaggerAnnotator(opennlp.tools.postag.POSTagger tagger)

Initializes the adapter.

Parameters:

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

Throws:

IllegalArgumentException - Thrown if tagger is null.

Method Details

annotate

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

Tags the document sentence by sentence and adds the Layers.POS_TAGS layer.

For every sentence, the tokens whose spans lie inside the sentence span are tagged as one sequence, and each tag is emitted on its token's span. The required layers must be present, but they may be empty: a document without sentences or tokens yields a present-but-empty tag layer, and a sentence containing no tokens contributes nothing.

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 and Layers.TOKENS layers, with every token lying inside a sentence.

Returns:

A new Document with the Layers.POS_TAGS layer added. Never null.

Throws:

IllegalArgumentException - Thrown if document is null, the sentence layer or the token layer is absent, a token lies outside every sentence, or the tagger does not return one tag per token of a sentence.

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