| package backtype.storm.testing; |
| |
| import backtype.storm.task.TopologyContext; |
| import backtype.storm.topology.OutputFieldsDeclarer; |
| import backtype.storm.topology.base.BaseBatchBolt; |
| import backtype.storm.coordination.BatchOutputCollector; |
| import backtype.storm.tuple.Fields; |
| import backtype.storm.tuple.Tuple; |
| import backtype.storm.tuple.Values; |
| import backtype.storm.utils.Utils; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| public class KeyedCountingBatchBolt extends BaseBatchBolt { |
| BatchOutputCollector _collector; |
| Object _id; |
| Map<Object, Integer> _counts = new HashMap<Object, Integer>(); |
| |
| @Override |
| public void prepare(Map conf, TopologyContext context, BatchOutputCollector collector, Object id) { |
| _collector = collector; |
| _id = id; |
| } |
| |
| @Override |
| public void execute(Tuple tuple) { |
| Object key = tuple.getValue(1); |
| int curr = Utils.get(_counts, key, 0); |
| _counts.put(key, curr + 1); |
| } |
| |
| @Override |
| public void finishBatch() { |
| for(Object key: _counts.keySet()) { |
| _collector.emit(new Values(_id, key, _counts.get(key))); |
| } |
| } |
| |
| @Override |
| public void declareOutputFields(OutputFieldsDeclarer declarer) { |
| declarer.declare(new Fields("tx", "key", "count")); |
| } |
| |
| } |