I believe it is a matter of specification compliance, not
implementation, that data sources are made available only to EJBs. The
reason is that the DataSource is neither Remote or Serializable. So to
make it globally available in JNDI would mean that a client could look
up an object which it could not access. What's the point? So, you ask,
why not make DataSource extend Remote? Because the JDBC implementations
would then all have to be Serializable or Remote, which they aren't, and
aren't about to be. Some of them _may_ be, and you can use them, and
hack the JNDI tree to make them available to clients. Then try to
change the underlying database - ooops! have to re-design the whole
application, because the customer needs Oracle's scalability, but their
JDBC driver is not Remote!
Standards compliance - a beautiful, wonderful thing.
Tom
Edward Wang wrote:
>
> How can you access DataSource from a servlet? I tried but only got a
>"NameNotFoundException". I listed all the JNDI names within the Context, it didn't
>contains
> the JNDI name of my DataSource I saw that JBoss bound it to at the startup, like
>"java:/oraceDS".
>
> Did you do just as those who deploy any servlet in an WAR then in an EAR? I used
>Weblogic before for more than one year, and I found, and you will find too, it's
>really very convenient in this case of matters. You should code as you like, in
>Servlet, in JSP, or even in an Application, then just run it, for a servlet/jsp, you
>need only copy the compiled .class file to the "SERVLET_CLASSES" directory. Then you
>got it! I use JBoss just because it's free. For our customer need a cheap one than
>weblogic, it's too expensive! But I never imagined JBoss is so frustrating...
>
> ----- Original Message -----
> From: "Allen Fogleson" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Saturday, June 09, 2001 1:10 AM
> Subject: RE: [JBoss-user] Lookup Datasource from Javabeans. Possible?
>
> > Hmm I have no problem accessing the DataSource from a servlet, or JSP. There
> > is at least one good reason to do this, taking advantage of connection
> > pooling without having to write your own pool. Someone else reccommended
> > against it (if i interpreted correctly) but I see no reason to NOT use the
> > DataSource. This is what making the application portable is about. imagine
> > that i have to do the traditional
> >
> > class.forName(driver).newInstance();
> > DriverManager......
> >
> > EVERY time I want to go to the DB? then if the DB changes I now have to
> > change all that code. Even with a properties file this is more painful than
> > simply change the DataSource definition once. (Admittedly there should be at
> > most 2 changes using a properties file method.) but 6 months down the road
> > when someone else is doing the maintenance of your code will they remember
> > to make the change?
> >
> > Al
> >
> >
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]]On Behalf Of Edward Wang
> > Sent: Friday, June 08, 2001 4:15 AM
> > To: [EMAIL PROTECTED]
> > Subject: Re: [JBoss-user] Lookup Datasource from Javabeans. Possible?
> >
> >
> > If the JBoss/Tomcat pack even doesn't allow my servlet to access Datasource,
> > then why would I use JBoss but not JRun or something else?
> > For that, I have to write an EJB for every little piece of SQL I want to
> > execute in my DB in my servlet. Is that too inconvient?
> >
> > ----- Original Message -----
> > From: "Guy Rouillier" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Sent: Friday, June 08, 2001 2:16 PM
> > Subject: Re: [JBoss-user] Lookup Datasource from Javabeans. Possible?
> >
> >
> > See numerous messages in the archives on this subject. The connection pool
> > is meant to be used by EJBs running within JBoss, not by external clients.
> > Won't work - connections are set up within a JVM context, and your external
> > client is in another JVM.
> >
> > I don't know if there is some hack to make this work with the integrated
> > packages (JBoss+Tomcat or JBoss+Jetty), but even if you can you shouldn't.
> >
> > ----- Original Message -----
> > From: "Edward Wang" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Sent: Thursday, June 07, 2001 9:44 PM
> > Subject: Re: [JBoss-user] Lookup Datasource from Javabeans. Possible?
> >
> >
> > > Seems impossible. When I was trying to connect to a Datasource that I saw
> > was bound to java:/instantDB by JBoss at the startup in my servlet.
> > > But the following error was reported:
> > >
> > > Connection error:javax.naming.NameNotFoundException: InstandDB not bound
> > >
> > > Does this mean that?
> > >
> > > Edward
> > >
> > > ----- Original Message -----
> > > From: "Dexter Legaspi" <[EMAIL PROTECTED]>
> > > To: <[EMAIL PROTECTED]>
> > > Sent: Thursday, June 07, 2001 9:57 PM
> > > Subject: Re: [JBoss-user] Lookup Datasource from Javabeans. Possible?
> > >
> > >
> > > >
> > > > yes!
> > > >
> > > > --- Tim Yates <[EMAIL PROTECTED]> wrote:
> > > > > Is it possible to lookup the Datasource from my
> > > > > JavaBeans?
> > > > >
> > > > > I use direct SQL to improve performance in several
> > > > > methods, and wondered if
> > > > > I could use the connection pool from my BMP beans...
> > > > >
> > > > > Cheers.
> > > > >
> > > > > Tim.
> > > > >
> > > > >
> > > > > _______________________________________________
> > > > > JBoss-user mailing list
> > > > > [EMAIL PROTECTED]
> > > > >
> > > > http://lists.sourceforge.net/lists/listinfo/jboss-user
> > > >
> > > >
> > > > __________________________________________________
> > > > Do You Yahoo!?
> > > > Get personalized email addresses from Yahoo! Mail - only $35
> > > > a year! http://personal.mail.yahoo.com/
> > > >
> > > > _______________________________________________
> > > > JBoss-user mailing list
> > > > [EMAIL PROTECTED]
> > > > http://lists.sourceforge.net/lists/listinfo/jboss-user
> > > >
> > > $--$~z?y-S
> >
> >
> > _______________________________________________
> > JBoss-user mailing list
> > [EMAIL PROTECTED]
> > http://lists.sourceforge.net/lists/listinfo/jboss-user
> >
> > $--$~z?ib,y+b?-+-Sw6ˬ
> >
> >
> > _______________________________________________
> > JBoss-user mailing list
> > [EMAIL PROTECTED]
> > http://lists.sourceforge.net/lists/listinfo/jboss-user
> >
> , f)+-$
_______________________________________________
JBoss-user mailing list
[EMAIL PROTECTED]
http://lists.sourceforge.net/lists/listinfo/jboss-user
