/**
* 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 storm.starter;
import backtype.storm.Config;
import backtype.storm.LocalCluster;
import backtype.storm.LocalDRPC;
import backtype.storm.drpc.DRPCSpout;
import backtype.storm.drpc.ReturnResults;
import backtype.storm.topology.BasicOutputCollector;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.TopologyBuilder;
import backtype.storm.topology.base.BaseBasicBolt;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;
public class ManualDRPC {
public static class ExclamationBolt extends BaseBasicBolt {
@Override
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("result", "return-info"));
}
@Override
public void execute(Tuple tuple, BasicOutputCollector collector) {
String arg = tuple.getString(0);
Object retInfo = tuple.getValue(1);
collector.emit(new Values(arg + "!!!", retInfo));
}
}
public static void main(String[] args) {
TopologyBuilder builder = new TopologyBuilder();
LocalDRPC drpc = new LocalDRPC();
DRPCSpout spout = new DRPCSpout("exclamation", drpc);
builder.setSpout("drpc", spout);
builder.setBolt("exclaim", new ExclamationBolt(), 3).shuffleGrouping("drpc");
builder.setBolt("return", new ReturnResults(), 3).shuffleGrouping("exclaim");
LocalCluster cluster = new LocalCluster();
Config conf = new Config();
cluster.submitTopology("exclaim", conf, builder.createTopology());
System.out.println(drpc.execute("exclamation", "aaa"));
System.out.println(drpc.execute("exclamation", "bbb"));
}
}