Re: Exception handling in Spring-MVC/FreeMarker web applications

I solved this problem a few days ago, without the use of a custom handler.
Just for completeness, and in case any other FreeMarker freaks need to do
the same thing in a Spring-MVC web application, here's the how:

1 - you need an error-page element in your web.xml:

<error-page>
  <error-code>500</error-code>
  <location>/e500.ftl</location>
</error-page>

(In my case, the *.ftl extension is servlet-mapped to the Spring
dispatcher; e500.ftl is my FreeMarker template error page.)

2 - In the Spring configuration, you need to set the correct handler:

<bean id="freemarkerConfig"

class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">
  <property name="freemarkerSettings">
    <props>
      <prop key="template_exception_handler">rethrow</prop>
...

Setting the handler to "rethrow" gets things working exactly the way I want
- template exceptions show my 500 page without a stack trace, and of course
the log file captures the stack trace so I have it for analysis. For
development I can set this to "html_debug", which displays a stack trace I
can use.

Thanks to Daniel Dekany and John Newman for getting me on the right track
with this.

--Pete

Daniel Dekany <[email protected]> wrote on 10/26/2009 11:58:49 AM:

> Monday, October 26, 2009, 5:10:40 PM, [email protected] wrote:
>
> > It looks like it needs a custom handler. It's actually quite easy to
set
> > the handler in the Spring configuration, but setting it to use the
Rethrow
> > handler results in either a stack trace in the browser or a blank page,
> > depending upon whether or not you have an "error-page" element in the
> > web.xml to trap 500 errors (with this element in place you get a blank
> > page).
>
> Just in case you missed it, FreeMarker itself logs the exception. So,
> the blank(ish) page might not that bad. (Of course it should not be
> really blank, I should say "Sorry, an error has occurred on the
> server" etc.)
>
> > Daniel Dekany <[email protected]> wrote on 10/22/2009 01:01:43 AM:
> >
> >> Wednesday, October 21, 2009, 10:25:53 PM, [email protected] wrote:
> >>
> >> > Maybe... but if the handler rethrows the exception, what catches it
in
> > the
> >> > SpringMVC environment?
> >>
> >> I don't know... that's in the hands of Spring MVC. If it doesn't
> >> handle it properly, you may try to pull some dirty trick in a custom
> >> TemplateExceptionHandler implementation, although best would be if the
> >> thing is fixed in Spring MVC then.
> >>
> >> > How would my app know to force a 500 error response
> >> > back to the client? I'm trying to get my brain round that. I think I
> > need
> >> > to experiment a bit.
> >> >
> >> > Daniel Dekany <[email protected]> wrote on 10/21/2009 02:08:39 PM:
> >> >
> >> >> Wednesday, October 21, 2009, 9:58:17 PM, [email protected] wrote:
> >> >>
> >> >> > That's great. I think I need either IGNORE_HANDLER or perhaps
> > develop
> >> > my
> >> >> > own custom handler. Either way, this is the key. Thanks!
> >> >>
> >> >> Nah, certainly you want the "rethrow" handler... Unless you want
buggy
> >> >> templates to return a some half-done response without showing any
> >> >> error message to the user.
> >> >>
> >> >> > "Newman, John W" <[email protected]> wrote on
10/21/2009
> >> > 01:13:57
> >> >> > PM:
> >> >> >
> >> >> >> Hi -
> >> >> >>
> >> >> >> Take a look at
> >> >> >>
> >> >> >>       configuration.
> >> >> >>
> > setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
> >> >> >>
> >> >> >> RETHROW_HANDLER may not be what you want ... I forget what each
> >> >> >> does, there are a few different options.  But that's the setting
> >> > you're
> >> >> > after
> >> >> >>
> >> >> >> -----Original Message-----
> >> >> > [snip]
> >> >> >
> >> >> >
> >> >> >
> >> >>
> >> >>
> >> >> --
> >> >> Best regards,
> >> >>  Daniel Dekany
> >>
> >> --
> >> Best regards,
> >>  Daniel Dekany
> >>
> >>
> >>
> >
>
------------------------------------------------------------------------------

> >
> >> Come build with us! The BlackBerry(R) Developer Conference in SF, CA
> >> is the only developer event you need to attend this year. Jumpstart
your
> >> developing skills, take BlackBerry mobile applications to market and
stay
> >
> >> ahead of the curve. Join us from November 9 - 12, 2009. Register now!
> >> http://p.sf.net/sfu/devconference
> >> _______________________________________________
> >> FreeMarker-user mailing list
> >> [email protected]
> >> https://lists.sourceforge.net/lists/listinfo/freemarker-user
> >
> >
> >
>
------------------------------------------------------------------------------

> > Come build with us! The BlackBerry(R) Developer Conference in SF, CA
> > is the only developer event you need to attend this year. Jumpstart
your
> > developing skills, take BlackBerry mobile applications to market and
stay
> > ahead of the curve. Join us from November 9 - 12, 2009. Register now!
> > http://p.sf.net/sfu/devconference
> > _______________________________________________
> > FreeMarker-user mailing list
> > [email protected]
> > https://lists.sourceforge.net/lists/listinfo/freemarker-user
> >
>
> --
> Best regards,
>  Daniel Dekany
>
>
>
------------------------------------------------------------------------------

> Come build with us! The BlackBerry(R) Developer Conference in SF, CA
> is the only developer event you need to attend this year. Jumpstart your
> developing skills, take BlackBerry mobile applications to market and stay

> ahead of the curve. Join us from November 9 - 12, 2009. Register now!
> http://p.sf.net/sfu/devconference
> _______________________________________________
> FreeMarker-user mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/freemarker-user


------------------------------------------------------------------------------
Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day 
trial. Simplify your report design, integration and deployment - and focus on 
what you do best, core application coding. Discover what's new with
Crystal Reports now.  http://p.sf.net/sfu/bobj-july