/*
* 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.tools.doccat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Map;
import opennlp.tools.util.featuregen.StringPattern;
/**
* Generates a feature for each word in a document.
*/
public class BagOfWordsFeatureGenerator implements FeatureGenerator {
private boolean useOnlyAllLetterTokens = false;
public BagOfWordsFeatureGenerator() {
}
BagOfWordsFeatureGenerator(boolean useOnlyAllLetterTokens) {
this.useOnlyAllLetterTokens = useOnlyAllLetterTokens;
}
@Override
public Collection<String> extractFeatures(String[] text, Map<String, Object> extraInformation) {
Collection<String> bagOfWords = new ArrayList<String>(text.length);
for (String word : text) {
if (useOnlyAllLetterTokens) {
StringPattern pattern = StringPattern.recognize(word);
if (pattern.isAllLetter())
bagOfWords.add("bow=" + word);
}
else {
bagOfWords.add("bow=" + word);
}
}
return bagOfWords;
}
}