// Copyright 2016 Twitter. All rights reserved.
//
// 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 com.twitter.heron.integration_test.common.bolt;
import java.util.Map;
import com.twitter.heron.api.bolt.OutputCollector;
import com.twitter.heron.api.topology.OutputFieldsDeclarer;
import com.twitter.heron.api.topology.TopologyContext;
import com.twitter.heron.api.tuple.Fields;
import com.twitter.heron.api.tuple.Tuple;
import com.twitter.heron.api.tuple.Values;
import com.twitter.heron.integration_test.core.BaseBatchBolt;
/**
* A bolt will increase the field "received" when executes once.
* And it finally will emit the number of received tuples
*/
public class IncrementBolt extends BaseBatchBolt {
private static final long serialVersionUID = 1094032885033452863L;
private OutputCollector collector;
private int received = 0;
@Override
public void prepare(Map<String, Object> map,
TopologyContext topologyContext,
OutputCollector outputCollector) {
collector = outputCollector;
}
@Override
public void execute(Tuple tuple) {
received++;
}
@Override
public void finishBatch() {
collector.emit(new Values(received));
}
@Override
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("count"));
}
}