LinkFilterBolt.java

package com.ebottabi.bolt;

import java.util.Map;

import twitter4j.Status;
import twitter4j.URLEntity;

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

/**
 * Bolt that will emit those twitter status that have urls on it.
 *
 * @author ebot
 *
 */
public class LinkFilterBolt implements IRichBolt {

    OutputCollector collector;

    @Override
    public void prepare(Map stormConf, TopologyContext context,
            OutputCollector collector) {
        this.collector = collector;

    }

    @Override
    public void execute(Tuple tuple) {
        Status status = (Status) tuple.getValue(0);
        URLEntity urls[] = status.getURLEntities();

        if (urls != null && urls.length > 0) {
            collector.emit(tuple, new Values(status));
            collector.ack(tuple);
        }

    }

    @Override
    public void cleanup() {
    }

    @Override
    public void declareOutputFields(OutputFieldsDeclarer declarer) {
        declarer.declare(new Fields("tweets"));

    }

    @Override
    public Map<String, Object> getComponentConfiguration() {
        return null;
    }
}