/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package opennlp.uima.postag;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import opennlp.tools.postag.POSModel;
import opennlp.tools.postag.POSTaggerME;
import opennlp.uima.util.AnnotationComboIterator;
import opennlp.uima.util.AnnotationIteratorPair;
import opennlp.uima.util.AnnotatorUtil;
import opennlp.uima.util.UimaUtil;
import org.apache.uima.UimaContext;
import org.apache.uima.analysis_component.CasAnnotator_ImplBase;
import org.apache.uima.analysis_engine.AnalysisEngineProcessException;
import org.apache.uima.cas.CAS;
import org.apache.uima.cas.Feature;
import org.apache.uima.cas.Type;
import org.apache.uima.cas.TypeSystem;
import org.apache.uima.cas.text.AnnotationFS;
import org.apache.uima.resource.ResourceAccessException;
import org.apache.uima.resource.ResourceInitializationException;
import org.apache.uima.util.Level;
import org.apache.uima.util.Logger;
/**
* OpenNLP Part Of Speech annotator.
* <p>
* Mandatory parameters
* <table border=1>
* <tr><th>Type</th> <th>Name</th> <th>Description</th></tr>
* <tr><td>String</td> <td>opennlp.uima.ModelName</td> <td>The name of the model file</td></tr>
* <tr><td>String</td> <td>opennlp.uima.SentenceType</td> <td>The full name of the sentence type</td></tr>
* <tr><td>String</td> <td>opennlp.uima.TokenType</td> <td>The full name of the token type</td></tr>
* <tr><td>String</td> <td>opennlp.uima.POSFeature</td> <td>The name of the token pos feature,
* the feature must be of type String</td></tr>
* </table>
* <p>
* Optional parameters
* <table border=1>
* <tr><th>Type</th> <th>Name</th> <th>Description</th></tr>
* <tr><td>String</td> <td>opennlp.uima.ProbabilityFeature</td> <td>The name of the double probability feature (not set by default)</td></tr>
* <tr><td>Integer</td> <td>opennlp.uima.BeamSize</td>
* <tr><td>String</td> <td>opennlp.uima.DictionaryName</td> <td>The name of the dictionary file</td></tr>
* </table>
*/
public final class POSTagger extends CasAnnotator_ImplBase {
private POSTaggerME posTagger;
private Type sentenceType;
private Type tokenType;
private Feature posFeature;
private Feature probabilityFeature;
private UimaContext context;
private Logger logger;
/**
* Initializes a new instance.
*
* Note: Use {@link #initialize(UimaContext) } to initialize this instance. Not use the
* constructor.
*/
public POSTagger() {
// must not be implemented !
}
/**
* Initializes the current instance with the given context.
*
* Note: Do all initialization in this method, do not use the constructor.
*/
@Override
public void initialize(UimaContext context)
throws ResourceInitializationException {
super.initialize(context);
this.context = context;
this.logger = context.getLogger();
if (this.logger.isLoggable(Level.INFO)) {
this.logger.log(Level.INFO, "Initializing the OpenNLP "
+ "Part of Speech annotator.");
}
POSModel model;
try {
POSModelResource modelResource = (POSModelResource) context
.getResourceObject(UimaUtil.MODEL_PARAMETER);
model = modelResource.getModel();
} catch (ResourceAccessException e) {
throw new ResourceInitializationException(e);
}
Integer beamSize = AnnotatorUtil.getOptionalIntegerParameter(context,
UimaUtil.BEAM_SIZE_PARAMETER);
if (beamSize == null)
beamSize = POSTaggerME.DEFAULT_BEAM_SIZE;
this.posTagger = new POSTaggerME(model, beamSize, 0);
}
/**
* Initializes the type system.
*/
@Override
public void typeSystemInit(TypeSystem typeSystem) throws AnalysisEngineProcessException {
// sentence type
this.sentenceType = AnnotatorUtil.getRequiredTypeParameter(this.context, typeSystem,
UimaUtil.SENTENCE_TYPE_PARAMETER);
// token type
this.tokenType = AnnotatorUtil.getRequiredTypeParameter(this.context, typeSystem,
UimaUtil.TOKEN_TYPE_PARAMETER);
// pos feature
this.posFeature = AnnotatorUtil.getRequiredFeatureParameter(this.context, this.tokenType,
UimaUtil.POS_FEATURE_PARAMETER, CAS.TYPE_NAME_STRING);
this.probabilityFeature = AnnotatorUtil.getOptionalFeatureParameter(this.context,
this.tokenType, UimaUtil.PROBABILITY_FEATURE_PARAMETER, CAS.TYPE_NAME_DOUBLE);
}
/**
* Performs pos-tagging on the given tcas object.
*/
@Override
public void process(CAS tcas) {
final AnnotationComboIterator comboIterator = new AnnotationComboIterator(tcas,
this.sentenceType, this.tokenType);
for (AnnotationIteratorPair annotationIteratorPair : comboIterator) {
final List<AnnotationFS> sentenceTokenAnnotationList = new LinkedList<AnnotationFS>();
final List<String> sentenceTokenList = new LinkedList<String>();
for (AnnotationFS tokenAnnotation : annotationIteratorPair.getSubIterator()) {
sentenceTokenAnnotationList.add(tokenAnnotation);
sentenceTokenList.add(tokenAnnotation.getCoveredText());
}
final List<String> posTags = this.posTagger.tag(sentenceTokenList);
double posProbabilities[] = null;
if (this.probabilityFeature != null) {
posProbabilities = this.posTagger.probs();
}
final Iterator<String> posTagIterator = posTags.iterator();
final Iterator<AnnotationFS> sentenceTokenIterator = sentenceTokenAnnotationList.iterator();
int index = 0;
while (posTagIterator.hasNext() && sentenceTokenIterator.hasNext()) {
final String posTag = posTagIterator.next();
final AnnotationFS tokenAnnotation = sentenceTokenIterator.next();
tokenAnnotation.setStringValue(this.posFeature, posTag);
if (posProbabilities != null) {
tokenAnnotation.setDoubleValue(this.posFeature, posProbabilities[index]);
}
index++;
}
// log tokens with pos
if (this.logger.isLoggable(Level.FINER)) {
final StringBuilder sentenceWithPos = new StringBuilder();
sentenceWithPos.append("\"");
for (final AnnotationFS token : sentenceTokenAnnotationList) {
sentenceWithPos.append(token.getCoveredText());
sentenceWithPos.append('\\');
sentenceWithPos.append(token.getStringValue(this.posFeature));
sentenceWithPos.append(' ');
}
// delete last whitespace
if (sentenceWithPos.length() > 1) // not 0 because it contains already the " char
sentenceWithPos.setLength(sentenceWithPos.length() - 1);
sentenceWithPos.append("\"");
this.logger.log(Level.FINER, sentenceWithPos.toString());
}
}
}
/**
* Releases allocated resources.
*/
@Override
public void destroy() {
this.posTagger = null;
}
}