/** * 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; } }