Article:		Stateful Session EJBs: Beasts of Burden
Subject:		What about nearly static data?
Date:		2001-12-21 04:45:29
From:		jonathan.oconnor
I have a table containing information about the world's currencies (name, ISO code, decimal places, etc...) This information changes maybe once or twice a year. Most of my business logic needs to access this data often, so naturally I want to cache it. The $64 question is, how? My natuarl inclination is to create a singleton class (probably static methods) which reads teh DB table at initialization or first use. Then I just use this anywhere I need it. But what happens if I want to refresh the data? Can I use EJBs for a better solution? It should give fast access to the data. From reading your article, it seems that I shouldn't use a SFSB to do this. Very interested to hear your advice, Jonathan O'Connor

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• What about nearly static data?
  2005-08-10 11:44:25  palaniappan.rajaram [Reply | View]
  
  
  Hello Jonathan,
  
  Three and half years later I'm faced with the same design issue. I too have some static data which change once in a few days, in the middle of the regular hours of operation. Obviously, restarting when many users are logged in, is not an option.
  
  Have you found a better solution than a singleton? That was my original approach but refresh became a hassle. Now, I'm debating if I should use a "stateless" session bean (just one instance of it) which should have the following:
  
  - hashtable for the objects from the database
  - public getter method to retrieve an object
  - refresh method which when called should block access to the getter method until refresh is completed
  
  I would appreciate any feedback that you can provide.
  
  Thanks
  
  Raj
  prajaran@mindspring.com