Re: Please help: retrieval and proper usage of per thread DataContext

From: Joshua Pyle (joshua.t.pyl..mail.com)
Date: Wed Nov 30 2005 - 11:46:20 EST

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    Just incase this helps, this is all I do when getting a datacontext.

        public DataContext getDataContext() {
            DataContext context = null;
            try {
                context = DataContext.getThreadDataContext();
            } catch (IllegalStateException ex) {
                // Bind the DataContext
                context = DataContext.createDataContext();
                DataContext.bindThreadDataContext(context);
            }
            return context;
        }

    This is working great and essentially just gives me a DataContext that
    lives only during the request. I've found this is a great aproach for
    web based applications. 

    --
Joshua T. Pyle
Go has always existed.

    On 11/29/05, Andrus Adamchik <andru..bjectstyle.org> wrote:
> I confirmed - this is a bug in Jetty. I get the same results as you
> do on Jetty 5.1.3, while on Tomcat "requestInitialized" and
> "requestDestroyed" are being called just fine. Haven't tried Jetty 6
> yet.
>
> As a workaround that works on all servers with both servlet spec 2.3
> and 2.4, I suggest using WebApplicationContextFilter instead of the
> listener. Here is a snip from a sample web.xml
>
>
> <filter>
>     <filter-name>CayenneFilter</filter-name>
>     <filter-
> class>org.objectstyle.cayenne.conf.WebApplicationContextFilter</
> filter-class>
> </filter>
> <filter-mapping>
>     <filter-name>CayenneFilter</filter-name>
>     <url-pattern>/*</url-pattern>
> </filter-mapping>
>
> This is taken from Example #2 on Wiki:
>
> http://objectstyle.org/confluence/display/CAY/Cayenne+Examples)
>
> Andrus
>
> On Nov 30, 2005, at 3:45 AM, Joseph Hannon wrote:
> > Andrus,
> >
> > A little more testing- thanks for the debug tip!  I subclassed
> > WebApplicationContextProvider and overrode all the relevant methods
> > including "requestInitialized" to allow dubug log statements.
> > "requestInitialized" is not called for some reason, but methods
> > around it are.  My results are below.  I upgraded to Jetty 5.1.6 to
> > see if that would help, it did not.  Could try it in Tomcat to see
> > if there is any change, wouldn't expect a change.  I may need to do
> > as you suggest with ServletUtil.  I am also unaware of how to get
> > the session at that point.
> >
> > Joseph
> >
> > App startup:
> >
> > (main) DEBUG foo.bar.utility.DataContextProvider.<init>()
> > (main) DEBUG foo.bar.utility.DataContextProvider.contextInitialized()
> >
> > Going to Page 1 (reads from DB)
> >
> > (SunJsseListener1-1) DEBUG
> > foo.bar.utility.DataContextProvider.sessionCreated()
> > (SunJsseListener1-1) DEBUG
> > foo.bar.utility.DataContextProvider.getConfiguration()
> >
> > Submit Page 1
> > Going to Page 2 (reads from DB)
> > Submit Page 2  (writes to DB)
> >
> > (SunJsseListener1-0) DEBUG
> > foo.bar.utility.DataContextProvider.sessionDestroyed()
> >
> > Complete.
> >
>
>

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