stockDataRetrieval
Class NewsDownloader

java.lang.Object
  stockDataRetrieval.NewsDownloader

public class NewsDownloader

extends java.lang.Object

Singleton class that controls the downloading of the news stories for all stocks.

The object is triggered to activate a new thread or store it for later when a new ticker is added or when a previously spawned thread completes.

Field Summary

private int	MAX_NUM_THREADS the max number of news downloading threads allowed
private java.util.Vector	newsThreads a collection of threads that are waiting their turn to execute
private static int	numActiveThreads the nubmer of currently active threads
private static int	numCompletedThreads the number of completed threads
private static NewsDownloader	theInstance the instance of the NewsDownloader

Constructor Summary

private

NewsDownloader() Configure the downloader with a set max number of simultaneous threads

Method Summary

void	addTicker(java.lang.String newTicker) Add a new ticker for which to fetch a news story for
static NewsDownloader	getInstance() Return the instance of the singleton object
void	getStockNews(java.lang.String tickerFile) Retrieves files containing all news stories about a stock and stores it to a local directory.
private void	handleNotify() Whenever a new ticker name is added, this function enables the class to analyze the state of active threads and activate new threads or wait
void	notifyMe() When a thread previously spawned completes, the thread notifies the singleton via this method.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

theInstance

private static NewsDownloader theInstance

the instance of the NewsDownloader

MAX_NUM_THREADS

private int MAX_NUM_THREADS

the max number of news downloading threads allowed

newsThreads

private java.util.Vector newsThreads

a collection of threads that are waiting their turn to execute

numActiveThreads

private static int numActiveThreads

the nubmer of currently active threads

numCompletedThreads

private static int numCompletedThreads

the number of completed threads

Constructor Detail

NewsDownloader

private NewsDownloader()

Configure the downloader with a set max number of simultaneous threads

Method Detail

getInstance

public static NewsDownloader getInstance()

Return the instance of the singleton object

Returns:

The instance of the singleton NewsDonwloader

addTicker

public void addTicker(java.lang.String newTicker)

Add a new ticker for which to fetch a news story for

Parameters:

newTicker - The ticker for which to add to the list tickers to get news stories for

handleNotify

private void handleNotify()

Whenever a new ticker name is added, this function enables the class to analyze the state of active threads and activate new threads or wait

notifyMe

public void notifyMe()

When a thread previously spawned completes, the thread notifies the singleton via this method.

The function calls code to determine if a new thread should be spawned.

getStockNews

public void getStockNews(java.lang.String tickerFile)

Retrieves files containing all news stories about a stock and stores it to a local directory.

Parameters:

tickerFile - The name of the file containing all the ticker - company tuples which serves as the list of tickers to get the news for