SplitSentence.java

/**
 * Split Sentence is Bolt that splits a sentence given as a string and performs a split operation on the basis of punctuation 
 * characters and whitespaces as delimiters
 *
 *
 * @author Tarun Sharma
 * @version 1.0
 * @see <a href="http://www.dream-lab.in/">DREAM:Lab</a>
 *
 * Copyright 2014 DREAM:Lab, Indian Institute of Science, 2014
 *
 * Licensed 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 mypackage.bolts;

import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import backtype.storm.task.OutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseRichBolt;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;

public class SplitSentence extends BaseRichBolt{
	/**
	 * 
	 */
	private static final long serialVersionUID = 8026109946114772620L;

	private static Logger LOG = LoggerFactory.getLogger(SplitSentence.class);
			
	OutputCollector collector;
	String punct = "(\\p{Punct}|\\s)+";
	
	@Override
	public void prepare(Map stormConf, TopologyContext context,
			OutputCollector collector) {
		// TODO Auto-generated method stub
		this.collector = collector;
	}

	@Override
	public void execute(Tuple input) {
		// TODO Auto-generated method stub
		String sentence = input.getString(0);
		LOG.info("Inside Split anchors to ids is " + input.getMessageId().getAnchorsToIds());
		for (String word : sentence.split(punct)) {
			if (!word.equals("")) {
				word = word.toLowerCase();
				collector.emit(input, new Values(word+"<"));
			}
		}
		collector.ack(input);
	}

	@Override
	public void declareOutputFields(OutputFieldsDeclarer declarer) {
		// TODO Auto-generated method stub
		declarer.declare(new Fields("word"));
	}

}