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 com.alibaba.jstorm.flux.examples;
  
  import backtype.storm.task.TopologyContext;
  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;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import static backtype.storm.utils.Utils.tuple;
  
  
  /**
   * This bolt is used by the HBase example. It simply emits the first field
   * found in the incoming tuple as "word", with a "count" of `1`.
   *
   * In this case, the downstream HBase bolt handles the counting, so a value
   * of `1` will just increment the HBase counter by one.
   */
  public class WordCounter extends BaseBasicBolt {
      public static Logger LOG = LoggerFactory.getLogger(WordCounter.class);
  
      Map<String, Integer> _counts;
  
      public void prepare(Map stormConf, TopologyContext context) {
          _counts = new HashMap<String, Integer>();
      }
  
      public void execute(Tuple input, BasicOutputCollector collector) {
          String word = (String) input.getValues().get(0);
          int count = 0;
          if (_counts.containsKey(word)) {
              count = _counts.get(word);
          }
          count++;
          _counts.put(word, count);
          collector.emit(tuple(word, count));
      }
  
      public void cleanup() {
  
      }
  
      public void declareOutputFields(OutputFieldsDeclarer declarer) {
          declarer.declare(new Fields("word", "count"));
      }
  
  }
  