Re: Handling Database Connections

Hi James,

When Gary says:

However, if you're using WAS, you should be creating a data source

he's absolutely right. And that's true for any web or JEE container. So, if you're using servlets, EJB's, and so on, think a DataSource with a pool and JNDI.

I thought, and I believe most of us here did, that you had some kind of standalone app, probably threaded, for which you needed multiple connections.

I know there's an awful lot to learn and know about this stuff, but believe me, slower is faster ( even though your management might not want to accept that. ) There are lots of tutorials and articles out there ( I would be remiss if I didn't mention developerWorks, both to them and you ); a good place to visit is:

http://www.javapassion.com/


Joe Sam

Joe Sam Shirah - http://www.conceptgo.com
conceptGO - Consulting/Development/Outsourcing
Java Filter Forum: http://www.ibm.com/developerworks/java/
Just the JDBC FAQs: http://www.jguru.com/faq/JDBC
Going International? http://www.jguru.com/faq/I18N
Que Java400? http://www.jguru.com/faq/Java400

----- Original Message ----- From: "Gary L Peskin" <garyp@xxxxxxxxxxxx>
To: "'Java Programming on and around the iSeries / AS400'" <java400-l@xxxxxxxxxxxx>
Sent: Tuesday, November 25, 2008 10:52 PM
Subject: RE: Handling Database Connections

Classes here are loaded by the Web classloader. This should work as it
provides one classloader per web application, not per instance. It seems
like there might be something with the class that you coded up.

However, if you're using WAS, you should be creating a data source using the
administrative console and then looking up the data source via JNDI, not
creating your own connections to the database because these cannot be
managed by WAS. If you use the administration console, your data source
will be properly shared across all applications.

Have a look at
http://publib.boulder.ibm.com/infocenter/wasinfo/v6r1/index.jsp?topic=/com.i
bm.websphere.base.iseries.doc/info/iseries/ae/tdat_ccrtpds.html

Gary

-----Original Message-----
From: java400-l-bounces@xxxxxxxxxxxx

[mailto:java400-l-bounces@xxxxxxxxxxxx]

On Behalf Of James Perkins
Sent: Tuesday, November 25, 2008 7:12 PM
To: Java Programming on and around the iSeries / AS400
Subject: Re: Handling Database Connections

For the one I tested it on we are using WebSphere Application Server V6.0.
We also use V6.1 and probably soon V7.

I put the class in the normal WEB-INF/classes/ directory.

James R. Perkins


On Tue, Nov 25, 2008 at 17:46, Gary L Peskin <garyp@xxxxxxxxxxxx> wrote:

> What JSP/servlet container are you using (and what release)? You need

to

> be
> sure that your class is in the correct place so that it's only loaded

once.

>
> Gary
>
> > -----Original Message-----
> > From: java400-l-bounces@xxxxxxxxxxxx
> [mailto:java400-l-bounces@xxxxxxxxxxxx]
> > On Behalf Of James Perkins
> > Sent: Tuesday, November 25, 2008 5:25 PM
> > To: Java Programming on and around the iSeries / AS400
> > Subject: Re: Handling Database Connections
> >
> > Thanks all for your help. I did write a singleton to handle this, but

ran

> > into a problem.
> >
> > I'm not sure the singleton is being reused. I keep getting multiple
> > connections each time the class that uses the singleton is called.
> >
> > This class is called from a JSP, so maybe this has to do with the
> > classloader? I found an article JavaWorld that talks about this, but

I'm

> > still a bit confused.
> > http://www.javaworld.com/javaworld/jw-04-2003/jw-0425-
> > designpatterns.html?page=7
> >
> > Could someone kindly point me in the right direction. I have feeling

this

> > might be an easy thing, but I'm just not sure.
> >
> > James R. Perkins

--
This is the Java Programming on and around the iSeries / AS400 (JAVA400-L) mailing list
To post a message email: JAVA400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/java400-l
or email: JAVA400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/java400-l.