| /** |
| * 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.hbase.topology; |
| |
| import backtype.storm.task.TopologyContext; |
| import backtype.storm.topology.BasicOutputCollector; |
| import backtype.storm.topology.IBasicBolt; |
| import backtype.storm.topology.OutputFieldsDeclarer; |
| import backtype.storm.tuple.Fields; |
| import backtype.storm.tuple.Tuple; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.math.BigInteger; |
| import java.util.Map; |
| import java.util.Random; |
| |
| import static backtype.storm.utils.Utils.tuple; |
| |
| public class TotalWordCounter implements IBasicBolt { |
| |
| private BigInteger total = BigInteger.ZERO; |
| private static final Logger LOG = LoggerFactory.getLogger(TotalWordCounter.class); |
| private static final Random RANDOM = new Random(); |
| @SuppressWarnings("rawtypes") |
| public void prepare(Map stormConf, TopologyContext context) { |
| } |
| |
| /* |
| * Just output the word value with a count of 1. |
| * The HBaseBolt will handle incrementing the counter. |
| */ |
| public void execute(Tuple input, BasicOutputCollector collector) { |
| total = total.add(new BigInteger(input.getValues().get(1).toString())); |
| collector.emit(tuple(total.toString())); |
| //prints the total with low probability. |
| if(RANDOM.nextInt(1000) > 995) { |
| LOG.info("Running total = " + total); |
| } |
| } |
| |
| public void cleanup() { |
| LOG.info("Final total = " + total); |
| } |
| |
| public void declareOutputFields(OutputFieldsDeclarer declarer) { |
| declarer.declare(new Fields("total")); |
| } |
| |
| @Override |
| public Map<String, Object> getComponentConfiguration() { |
| return null; |
| } |
| |
| } |