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From William Kaufman <WKauf...@viquity.com>
Subject RE: Servlet/ Database Conenction Persists Question
Date Thu, 01 Jan 1970 00:00:00 GMT
> This is not really a jdbc issue.  What is happening is
> that my code specifies that the conenction to the
> database is made only during the init of the servlet
> and the conenction is closed after the servlet is
> destroyed.

Ah, OK.  Don't do that.

init() is called exactly once, when the servlet gets loaded.

If you want to close and re-allocate the connection, do it in your
doGet()/doPost()/doWhatever() methods (if you've overridden those) or in
your service() method (if you didn't): connect at the beginning,
commit/rollback and close at the end (preferrably in a "finally" block, to
make sure it gets done).

                                        -- Bill K. 

> -----Original Message-----
> From: A.L. [mailto:amoslieber@yahoo.com]
> Sent: Tuesday, August 07, 2001 10:27 AM
> To: tomcat-user@jakarta.apache.org
> Subject: RE: Servlet/ Database Conenction Persists Question
> 
> 
> This is not really a jdbc issue.  What is happening is
> that my code specifies that the conenction to the
> database is made only during the init of the servlet
> and the conenction is closed after the servlet is
> destroyed.  I think that my problem is that once I
> destroy the servlet, I can't figure a way to re
> initialize it.  Simply refreshing the servlet page
> doesn;t seem to work.
> --- William Kaufman <WKaufman@viquity.com> wrote:
> > >     I have developed a servlet web application
> > which
> > > connects to a database to retrieve information.  I
> > > noticed that if within my servlet I destroy the
> > > connection to the database there is no way to
> > > reconnect to the database .
> > 
> > Maybe this is a JSP thing (I'm not too familiar with
> > those), and JSPs have
> > some weird JDBC cover methods.  But you _should_ be
> > able to disconnect, by
> > calling Connection.close(); and to reconnect, the
> > same way you connected the
> > first time.
> > 
> > Why can't you reconnect?  Are you getting an
> > exception from
> > DriverManager.getConnection()?
> > 
> > >  Is keeping the persistent connection to the
> > database
> > > a heavy burden on tomcat?
> > 
> > Persistent connections aren't a burden on Tomcat,
> > but might be on your
> > database, especially if the modifications aren't
> > committed immediately.  You
> > should always try to close connections (and other
> > resources) if you don't
> > think you'll be using it again in a few seconds.
> > 
> > >   I don't believe my question pertains
> > specifically to
> > > Tomcat, so I was wondering whether or not any of
> > you
> > > knew where there are list servers which deal with
> > > servlets in general.
> > 
> > This mailing list is fine for general servlet
> > questions.  But this seems to
> > be a JDBC question,...
> > 
> >                                         -- Bill K. 
> > 
> > > -----Original Message-----
> > > From: A.L. [mailto:amoslieber@yahoo.com]
> > > Sent: Tuesday, August 07, 2001 9:07 AM
> > > To: tomcat-user@jakarta.apache.org
> > > Subject: Servlet/ Database Conenction Persists
> > Question
> > > 
> > > 
> > >     I have developed a servlet web application
> > which
> > > connects to a database to retrieve information.  I
> > > noticed that if within my servlet I destroy the
> > > connection to the database there is no way to
> > > reconnect to the database .  In other words I need
> > to
> > > keep my connection to the database at all times
> > that
> > > tomcat is up.  My questions include:
> > > 
> > >  Is this correct that there is no way to reconnect
> > to
> > > the database?  If this is not correct, how does
> > one
> > > reconnect, and or reinitialize the servlet?
> > >  Is keeping the persistent connection to the
> > database
> > > a heavy burden on tomcat?  In other words, is it
> > o.k.
> > > to design an application which never releases its
> > > conenction to the database?
> > >  
> > > 
> > >   I don't believe my question pertains
> > specifically to
> > > Tomcat, so I was wondering whether or not any of
> > you
> > > knew where there are list servers which deal with
> > > servlets in general.
> > > 
> > > __________________________________________________
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> 
> 
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