JoinSentimentsBolt.java

package com.zdatainc.rts.storm;

import org.apache.log4j.Logger;
import java.util.HashMap;
import backtype.storm.topology.BasicOutputCollector;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseBasicBolt;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;

public class JoinSentimentsBolt extends BaseBasicBolt
{
    private static final long serialVersionUID = 42L;
    private static final Logger LOGGER =
        Logger.getLogger(JoinSentimentsBolt.class);
    private HashMap<Long, Triple<String, Float, String>> tweets;

    public JoinSentimentsBolt()
    {
        this.tweets = new HashMap<Long, Triple<String, Float, String>>();
    }

    public void execute(Tuple input, BasicOutputCollector collector)
    {
        Long id = input.getLong(input.fieldIndex("tweet_id"));
        String text = input.getString(input.fieldIndex("tweet_text"));
        if (input.contains("pos_score"))
        {
            Float pos = input.getFloat(input.fieldIndex("pos_score"));
            if (this.tweets.containsKey(id))
            {
                Triple<String, Float, String> triple = this.tweets.get(id);
                if ("neg".equals(triple.getCar()))
                    emit(collector, id, triple.getCaar(), pos, triple.getCdr());
                else
                {
                    LOGGER.warn("one sided join attempted");
                    this.tweets.remove(id);
                }
            }
            else
                this.tweets.put(
                    id,
                    new Triple<String, Float, String>("pos", pos, text));
        }
        else if (input.contains("neg_score"))
        {
            Float neg = input.getFloat(input.fieldIndex("neg_score"));
            if (this.tweets.containsKey(id))
            {
                Triple<String, Float, String> triple = this.tweets.get(id);
                if ("pos".equals(triple.getCar()))
                    emit(collector, id, triple.getCaar(), neg, triple.getCdr());
                else
                {
                    LOGGER.warn("one sided join attempted");
                    this.tweets.remove(id);
                }
            }
            else
                this.tweets.put(
                    id,
                    new Triple<String, Float, String>("neg", neg, text));
        }
        else
            throw new RuntimeException("wat");
    }

    private void emit(
        BasicOutputCollector collector,
        Long id,
        String text,
        float pos,
        float neg)
    {
        collector.emit(new Values(id, pos, neg, text));
        this.tweets.remove(id);
    }

    public void declareOutputFields(OutputFieldsDeclarer declarer)
    {
        declarer.declare(new Fields("tweet_id",
                                    "pos_score",
                                    "neg_score",
                                    "tweet_text"));
    }
}