Re: [Springframework-rcp-dev] Bean methods that throw exceptions?

[Peter De B. <pet...@gm...>]

Indeed, I could add you as a writer, however I think it'd be better if this
stuff is put into the reference manual.

WDYT?


On 1/30/08, Jan Hoskens <jh...@sc...> wrote:
>
> Normally when any Exception pops up during the setting of a value, the
> exception is caught by the DefaultFormModel.ValidatingFormValueModel
> class and transformed to a bindingError. So if you get a error in your
> message area, it probably came from there. Note that there are some
> issues here: all listeners attached to the value change may also throw
> exceptions that are handled in the same manner. I did suggest a change
> here to provide an explicit binding exception that can be thrown in the
> accessStrategy to separate the good from the bad (so to speak). Normally
> this error should disappear if the value being set doesn't generate any
> exception. Does this work as expected?
>
> The getting of a value is another story. I don't think any handling is
> available at that point so an exception will probably be caught by the
> ExceptionHandler that you provide in your context.
>
> The developer blog was started by Peter. He could add you as a writer to
> the blog or we could post it in your name after a quick review. It would
> be nice to see some more stuff explained there.
>
> Additionally I've checked your project's website. It seems to be open
> source so I'm thinking of checking it out. It would be easier to
> actually see the problem than to write about it. I guess this isn't a
> problem?
>
> Kind Regards,
> Jan
>
> On Wed, 2008-01-30 at 11:27 +0200, Rogan Dawes wrote:
> > Geoffrey De Smet wrote:
> > > Forms are ussually meant for domain objects or transfer objects.
> > > Just like it's pretty impossible to try to jpa-persist a (heavy)
> > > business service or DAO instance.
> > >
> > > Wouldn't the use case you describe be better off if you
> > > initialize the encodedBody before showing the form?
> > >
> > > With kind regards,
> > > Geoffrey De Smet
> >
> > Let me give some more detail:
> >
> > This is for WebScarab-NG, which is an HTTP testing tool (including an
> > intercepting proxy).
> >
> > What I am modeling here is the HTTP Message (Request or Response), with
> > the following properties:
> >
> > "startLine" ("GET http://example.com HTTP/1.0" or "HTTP/1.0 200 ok")
> > "headers" (NamedValue[])
> > "rawBody"
> > "decodedBody"
> >
> > "decodedBody" is the result of applying the various transforms listed in
> > the "headers" (e.g "Transfer-Encoding: chunked" or "Content-Encoding:
> > gzip") to "rawBody". I don't actually store "decodedBody", but rather
> > update "rawBody" by applying the various transforms. Unfortunately, the
> > process of applying the transforms can generate IOExceptions, since I
> > push the data through (Input|Output)Streams such as GZIPInputStream.
> >
> > So, the idea is that the user can edit various properties of the HTTP
> > message before sending the message to the server, and this should
> > obviously include setting the "rawBody" (if desired) or "decodedBody"
> > (likely easier). Naturally, the two properties should remain in sync,
> > modulo the transforms.
> >
> > I have implemented PropertyChangeSupport for this object, so various
> > forms can be notified when the fields they are listening to are changed
> > as a result of other fields being modified. This is all working very
> well.
> >
> > The only problem now is what to do when the "(get|set)DecodedBody"
> > methods throw an Exception. My preference is simply to allow the user to
> > continue editing, with a warning/error message until no exception is
> thrown.
> >
> > Thanks for your help.
> >
> > Rogan
> >
> > P.S. is there an existing place to present the results of some of the
> > advice that I have received on this list? e.g. how to do the
> > Binder/Binding to String<->byte[], how to actually bind variables to
> > JComponents correctly, etc? I don't have my own blog (although I did
> > find http://spring-rich.blogspot.com/)
> >
> > >
> > > Rogan Dawes schreef:
> > >> Hi folks,
> > >>
> > >> I am trying to deal with a derived property that can throw an
> exception
> > >> when set (or even when "get").
> > >>
> > >> The method signature is:
> > >>
> > >>    byte[] getEncodedBody() throws IOException;
> > >>    void setEncodedBody(byte[] body) throws IOException;
> > >>
> > >> As suggested, there are some cases where invalid data will cause an
> > >> IOException to be thrown. When this happens, I get "methodInvocation"
> > >> showing up in my form message area.
> > >>
> > >> Is there some way of handling this exception, and propagating the
> > >> underlying exception to the user? This appears to be handled
> somewhere
> > >> in the BeanPropertyAccessStrategy or BeanWrapperImpl, although I
> can't
> > >> see exactly where.
> > >>
> > >> Any ideas?
> > >>
> > >> Rogan
> > >>
> > >>
> -------------------------------------------------------------------------
> > >> This SF.net email is sponsored by: Microsoft
> > >> Defy all challenges. Microsoft(R) Visual Studio 2008.
> > >> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
> > >
> > >
> > >
> -------------------------------------------------------------------------
> > > This SF.net email is sponsored by: Microsoft
> > > Defy all challenges. Microsoft(R) Visual Studio 2008.
> > > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
> > > _______________________________________________
> > > Springframework-rcp-dev mailing list
> > > Spr...@li...
> > > https://lists.sourceforge.net/lists/listinfo/springframework-rcp-dev
> > >
> > >
> >
> >
> >
> -------------------------------------------------------------------------
> > This SF.net email is sponsored by: Microsoft
> > Defy all challenges. Microsoft(R) Visual Studio 2008.
> > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
> > _______________________________________________
> > Springframework-rcp-dev mailing list
> > Spr...@li...
> > https://lists.sourceforge.net/lists/listinfo/springframework-rcp-dev
>
>
> **** DISCLAIMER ****
> http://www.schaubroeck.be/maildisclaimer.htm
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Microsoft
> Defy all challenges. Microsoft(R) Visual Studio 2008.
> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
> _______________________________________________
> Springframework-rcp-dev mailing list
> Spr...@li...
> https://lists.sourceforge.net/lists/listinfo/springframework-rcp-dev
>