Storm入门（四）WordCount示例
Storm API文档网址如下：
http://storm.apache.org/releases/current/javadocs/index.html
一、关联代码
使用maven，代码如下。
pom.xml 和Storm入门（三）HelloWorld示例相同
RandomSentenceSpout.java
/**
* 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 cn.ljh.storm.wordcount;
import org.apache.storm.spout.SpoutOutputCollector;
import org.apache.storm.task.TopologyContext;
import org.apache.storm.topology.OutputFieldsDeclarer;
import org.apache.storm.topology.base.BaseRichSpout;
import org.apache.storm.tuple.Fields;
import org.apache.storm.tuple.Values;
import org.apache.storm.utils.Utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;
import java.util.Random;
public class RandomSentenceSpout extends BaseRichSpout {
private static final Logger LOG = LoggerFactory.getLogger(RandomSentenceSpout.class);
SpoutOutputCollector _collector;
Random _rand;
public void open(Map conf, TopologyContext context, SpoutOutputCollector collector) {
_collector = collector;
_rand = new Random();
}
public void nextTuple() {
Utils.sleep(100);
String[] sentences = new String[]{
sentence("the cow jumped over the moon"),
sentence("an apple a day keeps the doctor away"),
sentence("four score and seven years ago"),
sentence("snow white and the seven dwarfs"),
sentence("i am at two with nature")};
final String sentence = sentences[_rand.nextInt(sentences.length)];
LOG.debug("Emitting tuple: {}", sentence);
_collector.emit(new Values(sentence));
}
protected String sentence(String input) {
return input;
}
@Override
public void ack(Object id) {
}
@Override
public void fail(Object id) {
}
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("word"));
}
// Add unique identifier to each tuple, which is helpful for debugging
public static class TimeStamped extends RandomSentenceSpout {
private final String prefix;
public TimeStamped() {
this("");
}
public TimeStamped(String prefix) {
this.prefix = prefix;
}
protected String sentence(String input) {
return prefix + currentDate() + " " + input;
}
private String currentDate() {
return new SimpleDateFormat("yyyy.MM.dd_HH:mm:ss.SSSSSSSSS").format(new Date());
}
}
}
WordCountTopology.java
/**
* 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 cn.ljh.storm.wordcount;
import org.apache.storm.Config;
import org.apache.storm.LocalCluster;
import org.apache.storm.StormSubmitter;
import org.apache.storm.task.OutputCollector;
import org.apache.storm.task.TopologyContext;
import org.apache.storm.topology.BasicOutputCollector;
import org.apache.storm.topology.IRichBolt;
import org.apache.storm.topology.OutputFieldsDeclarer;
import org.apache.storm.topology.TopologyBuilder;
import org.apache.storm.topology.base.BaseBasicBolt;
import org.apache.storm.tuple.Fields;
import org.apache.storm.tuple.Tuple;
import org.apache.storm.tuple.Values;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class WordCountTopology {
public static class SplitSentence implements IRichBolt {
private OutputCollector _collector;
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("word"));
}
public Map<String, Object> getComponentConfiguration() {
return null;
}
public void prepare(Map stormConf, TopologyContext context,
OutputCollector collector) {
_collector = collector;
}
public void execute(Tuple input) {
String sentence = input.getStringByField("word");
String[] words = sentence.split(" ");
for(String word : words){
this._collector.emit(new Values(word));
}
}
public void cleanup() {
// TODO Auto-generated method stub
}
}
public static class WordCount extends BaseBasicBolt {
Map<String, Integer> counts = new HashMap<String, Integer>();
public void execute(Tuple tuple, BasicOutputCollector collector) {
String word = tuple.getString(0);
Integer count = counts.get(word);
if (count == null)
count = 0;
count++;
counts.put(word, count);
collector.emit(new Values(word, count));
}
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("word", "count"));
}
}
public static class WordReport extends BaseBasicBolt {
Map<String, Integer> counts = new HashMap<String, Integer>();
public void execute(Tuple tuple, BasicOutputCollector collector) {
String word = tuple.getStringByField("word");
Integer count = tuple.getIntegerByField("count");
this.counts.put(word, count);
}
public void declareOutputFields(OutputFieldsDeclarer declarer) {
}
@Override
public void cleanup() {
System.out.println("-----------------FINAL COUNTS START-----------------------");
List<String> keys = new ArrayList<String>();
keys.addAll(this.counts.keySet());
Collections.sort(keys);
for(String key : keys){
System.out.println(key + " : " + this.counts.get(key));
}
System.out.println("-----------------FINAL COUNTS END-----------------------");
}
}
public static void main(String[] args) throws Exception {
TopologyBuilder builder = new TopologyBuilder();
builder.setSpout("spout", new RandomSentenceSpout(), 5);
//ShuffleGrouping：随机选择一个Task来发送。
builder.setBolt("split", new SplitSentence(), 8).shuffleGrouping("spout");
//FiledGrouping：根据Tuple中Fields来做一致性hash，相同hash值的Tuple被发送到相同的Task。
builder.setBolt("count", new WordCount(), 12).fieldsGrouping("split", new Fields("word"));
//GlobalGrouping：所有的Tuple会被发送到某个Bolt中的id最小的那个Task。
builder.setBolt("report", new WordReport(), 6).globalGrouping("count");
Config conf = new Config();
conf.setDebug(true);
if (args != null && args.length > 0) {
conf.setNumWorkers(3);
StormSubmitter.submitTopologyWithProgressBar(args[0], conf, builder.createTopology());
}
else {
conf.setMaxTaskParallelism(3);
LocalCluster cluster = new LocalCluster();
cluster.submitTopology("word-count", conf, builder.createTopology());
Thread.sleep(20000);
cluster.shutdown();
}
}
}
二、执行效果
