Storm实现单词统计案例

1. 需求

   实时统计发射到Storm框架中单词的总数

2. 分析

   设计一个topology，来实现对文档里面的单词出现的频率进行统计,整个topology分为三个部分

   (1)WordCountSpot:数据源,在已知的英文句子中,随机发送一条句子出去

   package 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 java.util.Map;
   
   //发送一条语句
   public class WordCountSpout extends BaseRichSpout {
   
       private SpoutOutputCollector collector;
   
       @Override
       public void open(Map conf, TopologyContext context, SpoutOutputCollector collector) {
   
           this.collector = collector;
   
       }
   
       @Override
       public void nextTuple() {
           //发送数据
           collector.emit(new Values("shnad zhang1 zhsndga1 dasd a a b b c dd d dd"));
   
           //延时0.5 s
           try {
               Thread.sleep(500);
           } catch (InterruptedException e) {
               e.printStackTrace();
           }
       }
   
       @Override
       public void declareOutputFields(OutputFieldsDeclarer declarer) {
   
           declarer.declare(new Fields("love"));
       }
   }
   

   (2)WordCountSplitBolt:负责将单行文本记录(句子),切分成单词

   package storm.wordcount;
   
   import org.apache.storm.task.OutputCollector;
   import org.apache.storm.task.TopologyContext;
   import org.apache.storm.topology.OutputFieldsDeclarer;
   import org.apache.storm.topology.base.BaseRichBolt;
   import org.apache.storm.tuple.Fields;
   import org.apache.storm.tuple.Tuple;
   import org.apache.storm.tuple.Values;
   
   import java.util.Map;
   
   public class WordCountSplitBolt extends BaseRichBolt{
       private OutputCollector collector;
       @Override
       public void prepare(Map stormConf, TopologyContext context, OutputCollector collector) {
   
           this.collector = collector;
       }
   
       @Override
       //接受数据
       public void execute(Tuple input) {
   
           //1. 获取数据
           String line = input.getString(0);
   
           //2 截取数据
           String[] splits = line.split(" ");
   
           //3 发送出去
           for (String word : splits) {
               collector.emit(new Values(word,1));
           }
       }
   
       @Override
       public void declareOutputFields(OutputFieldsDeclarer declarer) {
           //声明字段
           declarer.declare(new Fields("word", "num"));
       }
   }
   

   (3)WordCountBolt:负责对单词的频率进行累加

   package storm.wordcount;
   
   import org.apache.storm.task.OutputCollector;
   import org.apache.storm.task.TopologyContext;
   import org.apache.storm.topology.OutputFieldsDeclarer;
   import org.apache.storm.topology.base.BaseRichBolt;
   import org.apache.storm.tuple.Tuple;
   
   import java.util.HashMap;
   import java.util.Map;
   
   public class WordCountBolt extends BaseRichBolt {
       //单词为key,单词出现的次数为value
       private Map<String, Integer> map = new HashMap<>();
       private OutputCollector collector;
   
   
       @Override
       public void prepare(Map stormConf, TopologyContext context, OutputCollector collector) {
           this.collector = collector;
       }
   
       @Override
       public void execute(Tuple input) {
           //1 获取传递过来的数据
           String word = input.getString(0);
           Integer num = input.getInteger(1);
   
           //2 业务逻辑
           if (map.containsKey(word)) {
               //如果之前统计过有单词的个数,获取个数
               Integer count = map.get(word);
   
               map.put(word, count + num);
           } else {
               map.put(word, num);
           }
   
           // 3 控制台打印
           System.err.println(Thread.currentThread().getId() + " word : " + word + " num: " + map.get(word));
   
   
       }
   
       @Override
       public void declareOutputFields(OutputFieldsDeclarer declarer) {
       }
   }
   

   (4)WordCountMain驱动

   ​ 1.创建拓扑对象 2.设置spout 3.配置worker开启个数 4. 提交

   package storm.wordcount;
   
   import org.apache.storm.Config;
   import org.apache.storm.LocalCluster;
   import org.apache.storm.StormSubmitter;
   import org.apache.storm.topology.TopologyBuilder;
   import org.apache.storm.tuple.Fields;
   
   public class WordCountMain  {
       public static void main (String[] args){
           //1 创建拓扑
           TopologyBuilder builder = new TopologyBuilder();
           builder.setSpout("WordCountSpout",new WordCountSpout(),1);
           builder.setBolt("WordCountSplitBolt",new WordCountSplitBolt(),2).shuffleGrouping("WordCountSpout");
   
   
           builder.setBolt("WordCountBolt",new WordCountBolt(),4).fieldsGrouping("WordCountSplitBolt",new Fields("word"));
   
           //2 创建配置信息
           Config conf = new Config();
           conf.setNumWorkers(2);
   
           //3 提交
           if (args.length > 0){
               try {
                   StormSubmitter.submitTopology(args[0],conf,builder.createTopology());
               } catch (Exception e) {
                   e.printStackTrace();
               }
           }else {
               LocalCluster cluster = new LocalCluster();
               cluster.submitTopology("wordtopology",conf,builder.createTopology());
           }
       }
   }