Storm教程

Storm Yahoo

雅虎!财经是互联网领先的商业新闻和财经数据网站。它是雅虎的一部分!并提供任何人都可以访问的金融新闻、市场统计数据、国际市场数据和其他有关金融资源的信息。
如果您是已注册的 Yahoo!用户,然后您可以自定义 Yahoo!金融以利用其某些产品。雅虎! Finance API 用于从 Yahoo! 查询财务数据!
此 API 显示的数据与实时延迟 15 分钟,并每 1 分钟更新一次其数据库,以访问当前的股票相关信息。现在让我们以一家公司的实时场景为例,看看如何在股价低于 100 时发出警报。

Spout 创建

spout 的目的是获取公司的详细信息并将价格发送到螺栓。您可以使用以下程序代码来创建一个 spout。

编码:YahooFinanceSpout.java

import java.util.*;
import java.io.*;
import java.math.BigDecimal;
//import yahoofinace packages
import yahoofinance.YahooFinance;
import yahoofinance.Stock;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Values;
import backtype.storm.topology.IRichSpout;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.spout.SpoutOutputCollector;
import backtype.storm.task.TopologyContext;
public class YahooFinanceSpout implements IRichSpout {
   private SpoutOutputCollector collector;
   private boolean completed = false;
   private TopologyContext context;
  
   @Override
   public void open(Map conf, TopologyContext context, SpoutOutputCollector collector){
      this.context = context;
      this.collector = collector;
   }
   @Override
   public void nextTuple() {
      try {
         Stock stock = YahooFinance.get("INTC");
         BigDecimal price = stock.getQuote().getPrice();
         this.collector.emit(new Values("INTC", price.doubleValue()));
         stock = YahooFinance.get("GOOGL");
         price = stock.getQuote().getPrice();
         this.collector.emit(new Values("GOOGL", price.doubleValue()));
         stock = YahooFinance.get("AAPL");
         price = stock.getQuote().getPrice();
         this.collector.emit(new Values("AAPL", price.doubleValue()));
      } catch(Exception e) {}
   }
   @Override
   public void declareOutputFields(OutputFieldsDeclarer declarer) {
      declarer.declare(new Fields("company", "price"));
   }
   @Override
   public void close() {}
  
   public boolean isDistributed() {
      return false;
   }
   @Override
   public void activate() {}
   @Override
   public void deactivate() {}
   @Override
   public void ack(Object msgId) {}
   @Override
   public void fail(Object msgId) {}
   @Override
   public Map<String, Object> getComponentConfiguration() {
      return null;
   }
  
}

Bolt Creation

这里bolt的目的是在价格低于100时处理给定公司的价格。当股票价格低于100时,它使用Java Map对象将截止价格限制警报设置为 true ;否则为假。完整的程序代码如下-

编码:PriceCutOffBolt.java

import java.util.HashMap;
import java.util.Map;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Values;
import backtype.storm.task.OutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.IRichBolt;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.tuple.Tuple;
public class PriceCutOffBolt implements IRichBolt {
   Map<String, Integer> cutOffMap;
   Map<String, Boolean> resultMap;
  
   private OutputCollector collector;
   @Override
   public void prepare(Map conf, TopologyContext context, OutputCollector collector) {
      this.cutOffMap = new HashMap <String, Integer>();
      this.cutOffMap.put("INTC", 100);
      this.cutOffMap.put("AAPL", 100);
      this.cutOffMap.put("GOOGL", 100);
      this.resultMap = new HashMap<String, Boolean>();
      this.collector = collector;
   }
   @Override
   public void execute(Tuple tuple) {
      String company = tuple.getString(0);
      double price = tuple.getDouble(1);
      if(this.cutOffMap.containsKey(company)){
         Integer cutOffPrice = this.cutOffMap.get(company);
         if(price < cutOffPrice) {
            this.resultMap.put(company, true);
         } else {
            this.resultMap.put(company, false);
         }
      }
    
      collector.ack(tuple);
   }
   @Override
   public void cleanup() {
      for(Map.Entry<String, Boolean> entry:resultMap.entrySet()){
         System.out.println(entry.getKey()+" : " + entry.getValue());
      }
   }
   @Override
   public void declareOutputFields(OutputFieldsDeclarer declarer) {
      declarer.declare(new Fields("cut_off_price"));
   }
  
   @Override
   public Map<String, Object> getComponentConfiguration() {
      return null;
   }
  
}

Submitting a Topology

这是 YahooFinanceSpout.java 和 PriceCutOffBolt.java 连接在一起并生成拓扑的主要应用程序。以下程序代码显示了如何提交拓扑。

编码:YahooFinanceStorm.java

import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Values;
import backtype.storm.Config;
import backtype.storm.LocalCluster;
import backtype.storm.topology.TopologyBuilder;
public class YahooFinanceStorm {
   public static void main(String[] args) throws Exception{
      Config config = new Config();
      config.setDebug(true);
    
      TopologyBuilder builder = new TopologyBuilder();
      builder.setSpout("yahoo-finance-spout", new YahooFinanceSpout());
      builder.setBolt("price-cutoff-bolt", new PriceCutOffBolt())
         .fieldsGrouping("yahoo-finance-spout", new Fields("company"));
      
      LocalCluster cluster = new LocalCluster();
      cluster.submitTopology("YahooFinanceStorm", config, builder.createTopology());
      Thread.sleep(10000);
      cluster.shutdown();
   }
}

构建和运行应用程序

完整的应用程序包含三个 Java 代码。它们如下-
YahooFinanceSpout.java PriceCutOffBolt.java YahooFinanceStorm.java
可以使用以下命令构建应用程序-
javac-cp “/path/to/storm/apache-storm-0.9.5/lib/*”:”/path/to/yahoofinance/lib/*” *.java
可以使用以下命令运行应用程序-
javac-cp “/path/to/storm/apache-storm-0.9.5/lib/*”:”/path/to/yahoofinance/lib/*”:.
YahooFinanceStorm

输出

输出将类似于以下内容-
GOOGL : false
AAPL : false
INTC : true
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