Appendix: Using the Yahoo Service

10.1. Overview

What is an report without the correct data? Correct, nothing! We want to display the newest data of our favorite stock. Yahoo! Finance provides automatically generated CSV files of all stocks on the market. To get this we only have to download a file from this link http://ichart.finance.yahoo.com/table.csv?s=JAVA . It gives you a csv file with the history of the stock. As you can see, this "service" has the parameter s=JAVA with the name of the stock.

10.2. The Code

The following code is using the Apache HttpClient library. The Apache HttpClient library allow you to simulate a browser and send and receive HTTP data. Download the necessary libraries from http://hc.apache.org/

As the time of the writing HttpClient requires also additional libraries, currently they are described here: http://hc.apache.org/httpclient-3.x/dependencies.html

Download all required libraries and add them add them to your classpath.

Interesting for you is that we need the method updateHistory of the GetStocksHistory class with a string parameter(stock name) , which returns us a ArrayList.

   
package sawan.modi.stockticker;

import java.util.ArrayList;

public class StockHistory {
 ArrayList m_stockHistory;
 
 public StockHistory() {
  m_stockHistory = new ArrayList();
 }
 public void add (StockData data) {
  m_stockHistory.add(data);
 }
}

  

   
package sawan.modi.stockticker;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Iterator;
import java.util.Locale;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.methods.GetMethod;

public class GetStockHistory {

 SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd", Locale.US);

 NumberFormat nf = NumberFormat.getInstance(Locale.US);

 NumberFormat pf = NumberFormat.getInstance(Locale.US);

 StockHistory history = new StockHistory();

 public ArrayList updateHistory(String company) {

  Calendar from = Calendar.getInstance();
  Calendar to = Calendar.getInstance();
  to.set(2009, 01, 01);
  from.set(2006, 01, 01);
  System.out.println(to.toString());
  StringBuffer url = new StringBuffer(
    "http://ichart.finance.yahoo.com/table.csv" + "?s=");
  url.append(company);

  try {
   HttpClient client = new HttpClient();
   client.getHostConfiguration().setProxy("proxy", 8080); // Delete
   // this Line
   // if you
   // don't use
   // a proxy
   client.getHttpConnectionManager().getParams().setConnectionTimeout(
     5000);
   System.out.println(url.toString());
   HttpMethod method = new GetMethod(url.toString());
   method.setFollowRedirects(true);
   client.executeMethod(method);
   BufferedReader in = new BufferedReader(new InputStreamReader(method
     .getResponseBodyAsStream()));
   // The first line is the header, ignoring
   String inputLine = in.readLine();

   while ((inputLine = in.readLine()) != null) {
    if (inputLine.startsWith("<"))
     continue;
    String[] item = inputLine.split(",");
    if (item.length < 6)
     continue;

    Calendar day = Calendar.getInstance();
    day.setTime(df.parse(item[0].replace("\"", "")));
    day.set(Calendar.HOUR, 0);
    day.set(Calendar.MINUTE, 0);
    day.set(Calendar.SECOND, 0);
    day.set(Calendar.MILLISECOND, 0);
    StockData data = new StockData();
    data.setOpen(Double.parseDouble(item[1].replace(',', '.')));
    data.setHigh(Double.parseDouble(item[2].replace(',', '.')));
    data.setLow(Double.parseDouble(item[3].replace(',', '.')));
    data.setClose(Double.parseDouble(item[4].replace(',', '.')));
    data.setVolume(Long.parseLong(item[5]));
    data.setDate(df.parse(item[0].replace("\"", "")));
    history.add(data);
   }
   in.close();
   return history.m_stockHistory;

  } catch (Exception e) {
   System.out.println(e.getMessage());
   return null;
  }

 }


 
 public static void main(String[] args) {
//  GetStockHistory gsh = new GetStockHistory();
//  ArrayList sd = gsh.getNewHistory();
//
//  for(int i=0;i < sd.size(); i++)
//  {
//   System.out.println(sd.get(i).getDate());
//  }
 }
}