Hi,
I am storing some resources used on global level, such as database
connection broker, in ServletContext.
I am not sure however how to destroy them.
The idea is that if this is the first time call, Controller Servlet init
function initializes global resources and puts them in servlet context, so
that all subsequent init functions reuse those resources. However I have a
problem on how to destroying these global resources.
Currently, my ActionServlet code has:
public void destroy ()
{
// !!! actually should not do it here, should put in servlet
context destroy
DbConnectionBroker dbConnBroker = (DbConnectionBroker )
getServletContext().getAttribute ("dbConnBroker");
if ( dbConnBroker != null )
dbConnBroker.destroy (); // destroy connection pool
super.destroy();
}
Servlet initialization funciton has the following fragment of code:
// !!!init DB pool, put it in servlet context
DbConnectionBroker dbConnBroker = (DbConnectionBroker )
getServletContext().getAttribute ("dbConnBroker");
if ( dbConnBroker == null ) {
// create one here
dbConnBroker = new
DbConnectionBroker(dbDriver,dbServer,dbLogin,dbPassword,
minConns,maxConns,logFile, maxConnTime);
getServletContext().setAttribute ("dbConnBroker",
dbConnBroker);
}
The problem is that from looking at this code I can see that every time
servlet is destroyed, it will unload global resources from servlet context,
thus rendering the whole servletContext approach irrelevant (and dangerous I
would say if there are other servlets reusing those resources). Of course,
every servlet instance during init will have to recreate it again.
I cannot avoid thinking of C++ where templates allowed smart reference
counting of classes, thus I would be able to see if global resources are
still in use (like auto_ptr STL template class and similar). However there
must be some easier approach in Java for this particular problem (maybe some
API call for servletcontext).
Vadim Shun
NEW Corp
Dulles, VA
===========================================================================
To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST".
Some relevant FAQs on JSP/Servlets can be found at:
http://java.sun.com/products/jsp/faq.html
http://www.esperanto.org.nz/jsp/jspfaq.html
http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
