/**
* 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"));
}
}