contextDestroyed and DataSource attribute question

[nico dotti]

I'm using a DataSource to allow for pooling MySQL5 connection via Tomcat 6. I have a ServletContextListener and I'm wondering what the standard way of dealing with 'cleanup' is. Here's what I have as a first attempt. Suggestion? Thanks all:

   
/* Remove DataSource and Logger attributes */
public void contextDestroyed (ServletContextEvent sce) {
 
    Logger logger = Logger)sce.getServletContext().getAttribute("dispatchLogger");
 
    try { 
         logger.logp(Level.INFO,"DBCPoolingListener", "contextDestroyed(ServletContextEven sce)", 
"Attempting to remove the DBCPool attribute");
 
/* Remove the DataSource attribute  */
sce.getServletContext().removeAttribute("DBCPool");
 
logger.logp(Level.INFO,"DBCPoolingListener","contextDestroyed(ServletContextEven sce)", "Finished removing the DBCPool attribute" + "...removing dispatchLogger attribute next...");
 
} catch (Exception e) {
    logger.logp(Level.SEVERE, "DBCPoolingListener",
"contextDestroyed",
"Problem removing Data Source",
e);
} finally {
 
/* Remove the Logger attribute */
sce.getServletContext  ().removeAttribute("dispatchLogger");
    }
}
 

[ January 24, 2008: Message edited by: nico dotti ]

[ January 24, 2008: Message edited by: nico dotti ]
[ January 24, 2008: Message edited by: nico dotti ]

[Jeanne Boyarsky]

Nico,
This looks like it is more about the servlet lifecycle than JDBC. I'm going to move it to our servlets forum.

[Bear Bibeault]

It looks to me like all that you are doing is a bunch of logging and removing application-scoped variables from the servlet context. This is wasted effort. The servlet context is about to go out of scope, and any scoped variables in application scope will go with it. it is completely unnecessary to remove them in a context listener.

[nico dotti]

So are you saying that the only things I need to close up are connections, statements, within my classes then right? What exactly does one use the contextDestroyed for then?

[Ben Souther]

It's for cleaning up any resources that need to be cleaned up.
If you're using container managed connection pooling or opening and closing your connections within your servlets, then there probably won't be much if anything to clean up.

If, on the other hand, you've implemented your own connection pooling or if you are using something other than JDBC for persistance (legacy databases, etc) and have initialize something when the app starts and clean it up when it closes, this would be a good place to do it. Also some people spawn new threads from their applications to perform periodic tasks. This would be a good place for code that shuts down those threads gracefully.

[nico dotti]

Ok, thanks for the input