After reading a lot about the abusive use of exceptions in Java and how you should let an exception bubble up through the different layers of an application, I've come to a point where I don't know what I am supposed to do with the potential errors my application can have.
Basically, I have a webservice which uses the DAO pattern to access data in my database. All of the database actions can throw a
As of today, I'm using a try catch to catch the
SQLException and then thow a specific defined exception called
ExceptionDAO that will be handle by the webservice to return a correct message to the users (a mobile application) of my webservice.
After reading a lot about how exception should be exceptional and should not be used in control flow, I've come up with a mixed understanding of what I should do to handle any errors:
- Use return codes for anything that is likely to happen (e.g. username already exists) and therefore, to comply with the DAO pattern, pass my business objects as parameters instead. I could also use a specific pair which would return the code + the business object instead. The webservice would then use the return code to display a specific message.
- Use checked exceptions for anything that I can't predict will happen and let them bubble up to the webservice to handle and return a message to the users. (e.g. SQLException that I can't predict : connection aborted)
- Let unchecked exceptions bubble up aswell and display a sort of 404 error in this case.
I also had a look at the null pattern but I don't think it suits this particular situation really well. I'm also concerned to not give too much information to the users, but rather useful and straight to the point information. Indeed, the messages returned by the webservice will be used by a mobile application to then display a message to the end-user.
I hope that I was clear enough about the problem I'm having, and I'm looking forward to your answers !
N.B. : This a repost of a subject I posted on stackoverflow, which relates to programming and not a language specific problem.