/**
* 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.mahout.vectorizer.document;
import java.io.IOException;
import java.io.StringReader;
import com.google.common.io.Closeables;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.mahout.common.StringTuple;
import org.apache.mahout.common.lucene.AnalyzerUtils;
import org.apache.mahout.vectorizer.DocumentProcessor;
/**
* Tokenizes a text document and outputs tokens in a StringTuple
*/
public class SequenceFileTokenizerMapper extends Mapper<Text, Text, Text, StringTuple> {
private Analyzer analyzer;
@Override
protected void map(Text key, Text value, Context context) throws IOException, InterruptedException {
TokenStream stream = analyzer.tokenStream(key.toString(), new StringReader(value.toString()));
CharTermAttribute termAtt = stream.addAttribute(CharTermAttribute.class);
stream.reset();
StringTuple document = new StringTuple();
while (stream.incrementToken()) {
if (termAtt.length() > 0) {
document.add(new String(termAtt.buffer(), 0, termAtt.length()));
}
}
stream.end();
Closeables.close(stream, true);
context.write(key, document);
}
@Override
protected void setup(Context context) throws IOException, InterruptedException {
super.setup(context);
String analyzerClassName = context.getConfiguration().get(DocumentProcessor.ANALYZER_CLASS,
StandardAnalyzer.class.getName());
try {
analyzer = AnalyzerUtils.createAnalyzer(analyzerClassName);
} catch (ClassNotFoundException e) {
throw new IOException("Unable to create analyzer: " + analyzerClassName, e);
}
}
}