TickSpout.java

/*
 * Copyright (C) 2014 The Calrissian Authors
 *
 * 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 org.calrissian.flowmix.core.storm.spout;

import java.util.Map;

import backtype.storm.spout.SpoutOutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseRichSpout;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Values;

public class TickSpout extends BaseRichSpout{

    private long sleepMillis;
    private SpoutOutputCollector collector;

    public TickSpout(long sleepMillis) {
        this.sleepMillis = sleepMillis;
    }

    @Override
    public void declareOutputFields(OutputFieldsDeclarer outputFieldsDeclarer) {
        outputFieldsDeclarer.declareStream("tick", new Fields());
    }

    @Override
    public void open(Map map, TopologyContext topologyContext, SpoutOutputCollector spoutOutputCollector) {
        this.collector = spoutOutputCollector;
    }

    @Override
    public void nextTuple() {
        collector.emit("tick", new Values());
        try {
            Thread.sleep(sleepMillis);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    }
}