MyTransactionBolt 1

package com.sxt.storm.transactional;

import java.util.Map;

import backtype.storm.coordination.BatchOutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseTransactionalBolt;
import backtype.storm.transactional.TransactionAttempt;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;

public class MyTransactionBolt extends BaseTransactionalBolt {
	private static final long serialVersionUID = 1L;
	Integer count = 0;
	BatchOutputCollector collector;
	TransactionAttempt tx ;
	@Override
	public void prepare(Map conf, TopologyContext context,
			BatchOutputCollector collector, TransactionAttempt id) {
		this.collector = collector;
		System.err.println("MyTransactionBolt prepare txid:"+id.getTransactionId() +";  attemptid: "+id.getAttemptId());
	}
	/**
	 * 处理batch中每一个tuple
	 */
	@Override
	public void execute(Tuple tuple) {

		tx = (TransactionAttempt) tuple.getValue(0);
		System.err.println("MyTransactionBolt TransactionAttempt txid:"+tx.getTransactionId() +";  attemptid:"+tx.getAttemptId());
		String log = tuple.getString(1);
		if (log != null && log.length()>0) {
			count ++ ;
		}
	}

	/**
	 * 同一个batch处理完成后，会调用一次finishBatch方法
	 */
	@Override
	public void finishBatch() {
		System.err.println("finishBatch: "+count );
		collector.emit(new Values(tx,count));
	}
	@Override
	public void declareOutputFields(OutputFieldsDeclarer declarer) {
		declarer.declare(new Fields("tx","count"));
	}

}