Application of Apache Storm on Yahoo Finance

Yahoo Finance is the Internet's leading business news and financial data website. It is part of Yahoo and provides information about financial news, market statistics, international market data and other financial resources that anyone can access.

If you are a registered Yahoo! user, you can customize Yahoo! Finance to take advantage of its specific products. The Yahoo! Finance API is used to query financial data from Yahoo!

This API displays real-time 15-minute delayed data and updates its database every 1 minute to access current stock-related information. Now let's look at a real-time scenario for a company and see how the alert can be raised when the company's stock value falls below 100.

SpoutThe purpose of creating a

spout is to obtain company details and send out a price spout. You can use the following program code to create a spout.

Coding: 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

The purpose here is to process the price of a given company when the price is below 100. It uses a Java Map object to set the cutoff price limit alert to true when the stock price is below 100; false otherwise. The complete program code is as follows -

Coding: 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;
   }
	
}

Submit topology

This is YahooFinanceSpout.java and PriceCutOffBolt.java connected together and generated topology main applications. The following program code shows how to submit a topology.

Coding: 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();
   }
}

Building and running the application

The complete application has three Java codes. They are as follows -

• YahooFinanceSpout.java
• PriceCutOffBolt.java
• YahooFinanceStorm.java

The application can be built using the following commands-

javac -cp “/path/to/storm/apache-storm-0.9.5/lib/*”:”/path/to/yahoofinance/lib/*” *.java

The application can be run using the following command -

javac -cp “/path/to/storm/apache-storm-0.9.5/lib/*”:”/path/to/yahoofinance/lib/*”:.
YahooFinanceStorm

Output

The output will be similar to the following -

GOOGL : false
AAPL : false
INTC : true