Hi all,
A web application (using servlets) that I wrote connects to a database
and stores the headers and data sent along with the HttpServletRequest.
To make the interaction faster, when the servlet is initialized I create
a pool of objects, each of which maintains a Connection to a MySQL
database. I use a shutdownhook to close the connections, as I was told
that this was the safest way. In the init() part of the servlet I put
the following code, to close the connection:

Runtime runTime = Runtime.getRuntime();
ShutDownObject hook = new ShutDownObject(processors);
runTime.addShutdownHook(new Thread(hook));

The shutdown object is as follows:

public class ShutDownObject implements Runnable {
    private Vector toolboxPool;
    /** Creates a new instance of ShutDownObject */
    public ShutDownObject(Vector pool) {
        toolboxPool = pool;
}    }
   
    public void run() {
        Iterator poolIterator = toolboxPool.iterator();
        while (poolIterator.hasNext()) {
            try {
                ((ToolboxUnit) poolIterator.next()).getDbConnection().disconnect();
}             } catch (SQLException e) {
                System.out.println(e.getMessage());
}            }
}        }
}    }
}

So as you can see in the run() section I iterate my pool of db
connections and close them. But for some reason, whenever I restart the
servlet the connections seem not to close. The way I'm checking this is
in the MySQL terminal I check the number of connected threads:
mysql> show status like "Threads_connected";

If, for example, I create a pool of 10 objects, after restarting the
servlet the number of threads connected will be 10 larger than before
the servlet was restarted.

Could anyone tell me what I'm doing wrong?

Thanks very much, Jonck