content: /**
   * 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.starter;
  
  import com.alibaba.starter.utils.Assert;
  
  import backtype.storm.Config;
  import backtype.storm.LocalCluster;
  import backtype.storm.LocalDRPC;
  import backtype.storm.drpc.LinearDRPCTopologyBuilder;
  import backtype.storm.topology.BasicOutputCollector;
  import backtype.storm.topology.OutputFieldsDeclarer;
  import backtype.storm.topology.base.BaseBasicBolt;
  import backtype.storm.tuple.Fields;
  import backtype.storm.tuple.Tuple;
  import backtype.storm.tuple.Values;
  
  /**
   * This topology is a basic example of doing distributed RPC on top of Storm. It
   * implements a function that appends a "!" to any string you send the DRPC
   * function.
   *
   * @see <a href="http://storm.apache.org/documentation/Distributed-RPC.html">
   *      Distributed RPC</a>
   */
  public class BasicDRPCTopology {
      public static class ExclaimBolt extends BaseBasicBolt {
          @Override
          public void execute(Tuple tuple, BasicOutputCollector collector) {
              String input = tuple.getString(1);
              collector.emit(new Values(tuple.getValue(0), input + "!"));
          }
          
          @Override
          public void declareOutputFields(OutputFieldsDeclarer declarer) {
              declarer.declare(new Fields("id", "result"));
          }
          
      }
      
      public static void testDrpc() {
          LinearDRPCTopologyBuilder builder = new LinearDRPCTopologyBuilder("exclamation");
          builder.addBolt(new ExclaimBolt(), 3);
          
          Config conf = new Config();
          
          LocalDRPC drpc = new LocalDRPC();
          LocalCluster cluster = new LocalCluster();
          
          cluster.submitTopology("drpc-demo", conf, builder.createLocalTopology(drpc));
          
          try {
              Thread.sleep(30000);
          } catch (InterruptedException e) {
              // TODO Auto-generated catch block
          }
          try {
              for (String word : new String[] { "hello", "goodbye" }) {
                  System.out.println("Result for \"" + word + "\": " + drpc.execute("exclamation", word));
              }
          } catch (Exception e) {
              e.printStackTrace();
              Assert.fail("Failed to run DRPC Test");
          }
          
          drpc.shutdown();
          cluster.shutdown();
      }
      
      public static void main(String[] args) throws Exception {
          
          testDrpc();
      }
  }
  