storm-compatibility-examples/src/java/org/apache/storm/examples/ExclamationTopology.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.storm.examples;

import java.time.Duration;
import java.util.Map;

import org.apache.storm.Config;
import org.apache.storm.LocalCluster;
import org.apache.storm.StormSubmitter;
import org.apache.storm.examples.spout.TestWordSpout;
import org.apache.storm.task.OutputCollector;
import org.apache.storm.task.TopologyContext;
import org.apache.storm.topology.OutputFieldsDeclarer;
import org.apache.storm.topology.TopologyBuilder;
import org.apache.storm.topology.base.BaseRichBolt;
import org.apache.storm.tuple.Fields;
import org.apache.storm.tuple.Tuple;
import org.apache.storm.tuple.Values;
import org.apache.storm.utils.Utils;

/**
 * This is a basic example of a Storm topology.
 */
public final class ExclamationTopology {

  private ExclamationTopology() {
  }

  public static void main(String[] args) throws Exception {
    TopologyBuilder builder = new TopologyBuilder();
    int parallelism = 2;

    int spouts = parallelism;
    builder.setSpout("word", new TestWordSpout(Duration.ofMillis(50)), spouts);
    int bolts = 2 * parallelism;
    builder.setBolt("exclaim1", new ExclamationBolt(), bolts)
        .shuffleGrouping("word");

    Config conf = new Config();
    conf.setDebug(true);
    conf.setMaxSpoutPending(10);
    conf.setMessageTimeoutSecs(600);
    conf.put(Config.TOPOLOGY_WORKER_CHILDOPTS, "-XX:+HeapDumpOnOutOfMemoryError");

    if (args != null && args.length > 0) {
      conf.setNumWorkers(parallelism);
      StormSubmitter.submitTopology(args[0], conf, builder.createTopology());
    } else {
      System.out.println("Topology name not provided as an argument, running in simulator mode.");
      LocalCluster cluster = new LocalCluster();
      cluster.submitTopology("test", conf, builder.createTopology());
      Utils.sleep(10000);
      cluster.killTopology("test");
      cluster.shutdown();
    }
  }

  public static class ExclamationBolt extends BaseRichBolt {
    private static final long serialVersionUID = -8306159767177544059L;
    private OutputCollector collector;

    @Override
    @SuppressWarnings({"HiddenField", "rawtypes"})
    public void prepare(Map stormConf, TopologyContext context,
                        OutputCollector collector) {
      this.collector = collector;

    }

    @Override
    public void execute(Tuple tuple) {
      collector.emit(tuple, new Values(tuple.getString(0) + "!!!"));
      collector.ack(tuple);
    }

    @Override
    public void declareOutputFields(OutputFieldsDeclarer declarer) {
      declarer.declare(new Fields("word"));
    }
  }
}