| /** |
| * 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.streams; |
| |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.Map; |
| import org.apache.storm.Config; |
| import org.apache.storm.StormSubmitter; |
| import org.apache.storm.spout.SpoutOutputCollector; |
| import org.apache.storm.streams.PairStream; |
| import org.apache.storm.streams.StreamBuilder; |
| import org.apache.storm.streams.operations.Reducer; |
| import org.apache.storm.streams.operations.mappers.PairValueMapper; |
| import org.apache.storm.streams.windowing.SlidingWindows; |
| import org.apache.storm.streams.windowing.Window; |
| import org.apache.storm.task.TopologyContext; |
| import org.apache.storm.topology.OutputFieldsDeclarer; |
| import org.apache.storm.topology.base.BaseRichSpout; |
| import org.apache.storm.topology.base.BaseWindowedBolt.Count; |
| import org.apache.storm.tuple.Fields; |
| import org.apache.storm.tuple.Values; |
| import org.apache.storm.utils.Utils; |
| |
| /** |
| * An example that shows the usage of {@link PairStream#groupByKeyAndWindow(Window)} |
| * and {@link PairStream#reduceByKeyAndWindow(Reducer, Window)}. |
| */ |
| public class GroupByKeyAndWindowExample { |
| public static void main(String[] args) throws Exception { |
| StreamBuilder builder = new StreamBuilder(); |
| |
| // a stream of stock quotes |
| builder.newStream(new StockQuotes(), new PairValueMapper<String, Double>(0, 1)) |
| /* |
| * The elements having the same key within the window will be grouped |
| * together and the corresponding values will be merged. |
| * |
| * The result is a PairStream<String, Iterable<Double>> with |
| * 'stock symbol' as the key and 'stock prices' for that symbol within the window as the value. |
| */ |
| .groupByKeyAndWindow(SlidingWindows.of(Count.of(6), Count.of(3))) |
| .print(); |
| |
| // a stream of stock quotes |
| builder.newStream(new StockQuotes(), new PairValueMapper<String, Double>(0, 1)) |
| /* |
| * The elements having the same key within the window will be grouped |
| * together and their values will be reduced using the given reduce function. |
| * |
| * Here the result is a PairStream<String, Double> with |
| * 'stock symbol' as the key and the maximum price for that symbol within the window as the value. |
| */ |
| .reduceByKeyAndWindow((x, y) -> x > y ? x : y, SlidingWindows.of(Count.of(6), Count.of(3))) |
| .print(); |
| |
| Config config = new Config(); |
| String topoName = GroupByKeyAndWindowExample.class.getName(); |
| if (args.length > 0) { |
| topoName = args[0]; |
| } |
| config.setNumWorkers(1); |
| StormSubmitter.submitTopologyWithProgressBar(topoName, config, builder.build()); |
| } |
| |
| private static class StockQuotes extends BaseRichSpout { |
| private final List<List<Values>> values = Arrays.asList( |
| Arrays.asList(new Values("AAPL", 100.0), new Values("GOOG", 780.0), new Values("FB", 125.0)), |
| Arrays.asList(new Values("AAPL", 105.0), new Values("GOOG", 790.0), new Values("FB", 130.0)), |
| Arrays.asList(new Values("AAPL", 102.0), new Values("GOOG", 788.0), new Values("FB", 128.0)) |
| ); |
| private SpoutOutputCollector collector; |
| private int index = 0; |
| |
| @Override |
| public void open(Map<String, Object> conf, TopologyContext context, SpoutOutputCollector collector) { |
| this.collector = collector; |
| } |
| |
| @Override |
| public void nextTuple() { |
| Utils.sleep(5000); |
| for (Values v : values.get(index)) { |
| collector.emit(v); |
| } |
| index = (index + 1) % values.size(); |
| } |
| |
| @Override |
| public void declareOutputFields(OutputFieldsDeclarer declarer) { |
| declarer.declare(new Fields("symbol", "price")); |
| } |
| } |
| } |