opennlp.tools.namefind.DictionaryNameFinder Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreemnets. 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.tools.namefind;
import java.util.LinkedList;
import java.util.List;
import opennlp.tools.dictionary.Dictionary;
import opennlp.tools.dictionary.Index;
import opennlp.tools.util.Span;
import opennlp.tools.util.StringList;
/**
* This is a dictionary based name finder, it scans text
* for names inside a dictionary.
*/
public class DictionaryNameFinder implements TokenNameFinder {
private Dictionary mDictionary;
private Index mMetaDictionary;
/**
* Initializes the current instance.
*
* @param dictionary
*/
public DictionaryNameFinder(Dictionary dictionary) {
mDictionary = dictionary;
mMetaDictionary = new Index(dictionary.iterator());
}
public Span[] find(String[] tokenStrings) {
List foundNames = new LinkedList();
for (int startToken = 0; startToken < tokenStrings.length; startToken++) {
Span foundName = null;
String tokens[] = new String[]{};
for (int endToken = startToken; endToken < tokenStrings.length; endToken++) {
String token = tokenStrings[endToken];
// TODO: improve performance here
String newTokens[] = new String[tokens.length + 1];
System.arraycopy(tokens, 0, newTokens, 0, tokens.length);
newTokens[newTokens.length - 1] = token;
tokens = newTokens;
if (mMetaDictionary.contains(token)) {
StringList tokenList = new StringList(tokens);
if (mDictionary.contains(tokenList)) {
foundName = new Span(startToken, endToken + 1);
}
}
else {
break;
}
}
if (foundName != null) {
foundNames.add(foundName);
}
}
return (Span[]) foundNames.toArray(new Span[foundNames.size()]);
}
public void clearAdaptiveData() {
// nothing to clear
}
}