org.apache.tika.parser.ner.opennlp.OpenNLPNameFinder Maven / Gradle / Ivy
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* 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 org.apache.tika.parser.ner.opennlp;
import opennlp.tools.namefind.NameFinderME;
import opennlp.tools.namefind.TokenNameFinderModel;
import opennlp.tools.util.Span;
import org.apache.tika.io.IOUtils;
import org.apache.tika.parser.ner.NERecogniser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* An implementation of {@link NERecogniser} that finds names in text using Open NLP Model.
* This implementation works with only one entity type. For chain this name finder instances,
* see {@link OpenNLPNERecogniser}
*/
public class OpenNLPNameFinder implements NERecogniser {
private static final Logger LOG = LoggerFactory.getLogger(OpenNLPNameFinder.class);
private final String nameType;
private final Set nameTypes;
private NameFinderME nameFinder;
private boolean available;
/**
* Creates OpenNLP name finder
* @param nameType the entity type recognised by the given NER model
* @param nerModelPath path to ner model
*/
public OpenNLPNameFinder(String nameType, String nerModelPath) {
this.nameTypes = Collections.singleton(nameType);
this.nameType = nameType;
InputStream nerModelStream = getClass().getClassLoader().getResourceAsStream(nerModelPath);
try {
if (nerModelStream != null){
TokenNameFinderModel model = new TokenNameFinderModel(nerModelStream);
this.nameFinder = new NameFinderME(model);
this.available = true;
} else {
LOG.warn("Couldn't find model from {} using class loader", nerModelPath);
}
} catch (IOException e) {
LOG.error(e.getMessage(), e);
} finally {
IOUtils.closeQuietly(nerModelStream);
}
LOG.info("{} NER : Available for service ? {}", nameType, available);
}
@Override
public boolean isAvailable() {
return available;
}
@Override
public Set getEntityTypes() {
return nameTypes;
}
public static String[] tokenize(String text){
//NOTE: replace this with a NLP tokenizer tool
//clean + split
return text.trim().replaceAll("(\\s\\s+)", " ").split("\\s");
}
@Override
public synchronized Map> recognise(String text) {
String[] tokens = tokenize(text);
return findNames(tokens);
}
/**
* finds names from given array of tokens
* @param tokens the tokens array
* @return map of EntityType -> set of entity names
*/
public Map> findNames(String[] tokens) {
Span[] nameSpans = nameFinder.find(tokens);
String[] names = Span.spansToStrings(nameSpans, tokens);
Map> result = new HashMap<>();
if (names != null && names.length > 0) {
result.put(nameType, new HashSet<>(Arrays.asList(names)));
}
nameFinder.clearAdaptiveData();
return result;
}
}