> -----Original Message----- > From: Janne Mattila [mailto:[EMAIL PROTECTED] > Sent: Wednesday, September 08, 2004 11:57 PM > To: [EMAIL PROTECTED] > Subject: RE: Proper place for validation > >
<snip> > > I am fully aware that this is probably not the "accepted" way > of doing this. > All advice seems to say to create specific exception classes for your > applications exceptions. I have just never really understood > what benefit it > _really_ brings. It would be nice to "see the light" though, > so I would not > have to be such a heretic anymore.... :) Creating an exception for each business rule allows you to remove any dependancy between presentation and other layers. Putting an english error message in an exception destiend for a non-english reader makes no sense. One answer is to use Java's built in i18n facilities, except that now you can't change your message resource without changing your business/dao tier, that doesn't sit well with trying to achieve complete separation between layers. However, if I throw an exception that indicates the rule broken, or the general issue, then my view layer can map the exception to the message. > > > >From: "Jim Barrows" <[EMAIL PROTECTED]> > >Reply-To: "Struts Users Mailing List" <[EMAIL PROTECTED]> > >To: "Struts Users Mailing List" <[EMAIL PROTECTED]> > >Subject: RE: Proper place for validation > >Date: Wed, 8 Sep 2004 08:52:05 -0700 > > > > > > > > > -----Original Message----- > > > From: Janne Mattila [mailto:[EMAIL PROTECTED] > > > Sent: Wednesday, September 08, 2004 3:49 AM > > > To: [EMAIL PROTECTED] > > > Subject: RE: Proper place for validation > > > > > > > > > Hmm, not a lot of comments on this. I guess there is a > > > consensus on the > > > matter (that, or no-one really gives a damn). > > > > > > A quick followup on this; how could I achieve both > > > > > > a) decoupling of my business classes from Struts > > > b) internationalization > > > > > > if I validate in my business class? > > > > > > 1) > > > if (alreadyExists(email)) { > > > throw new MyAppException("E-mail address already exists"); > > > > > > achieves a) but not b), and > > > > > > 2) > > > if (alreadyExists(email)) { > > > throw new MyAppException("errors.email.duplicate"); > > > >Simple, you throw EmailAlreadyExists( email), and catch > that, or use the > >exception handling ability of struts to give an appropriate > error message > >to the user. For system level stuff (ie DB is missing etc) > you inlcude a > >cause, but don't necessarily show it to the user. > > _________________________________________________________________ > Add photos to your messages with MSN 8. Get 2 months FREE*. > http://join.msn.com/?page=features/featuredemail > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
