How to handle java exception in user friendly way

Question

I'm developing a swing application and I'm a bit confused how can I handle exceptions for example lately a part of my code rename files, So when I was testing it I came up with a "you don't have permission to rename file" as I got it from print exception message. So How Could I express this message to user? and should I use JOptionPane message or just show it on the status bar?

Thanks

Answer 1

From your question it sounds like you already know how to handle the exception in the java sense. However you are looking for advice on how to react to exceptions once you have caught them.

In the specific example you give in your question I (as a user) would want that error presented quite clearly so a JOptionPane may be your best bet. I wouldn't just update the status bar as that is very close to silently failing and the user will just be left confused.

A personal rule of thumb is that if the user is likly to be waiting on the code to complete before getting on with their task then they must be informed of the failure strongly i.e. a modal box. If the failure is in a background task that the user can carry on without caring about, or the code can recover from it, or the code is going to retry, then I would go with the more subtle approach of the status bar or icon change depending on the UI.

Answer 2

To elaborate on a comment made by Kevin D - it really depends on your expected user audience. If they are technically proficient you can use the exception text as is. If not then I would prefix the message with "An error has occurred, please contact your technical support personnel with the following information: " then append the error message and ideally a unique identifier for locating an associated log entry... I often use a timestamp for this.

If you really want to get fancy you can email the tech support people with much more detail like the exception and full stack trace, copy of log entry, etc. I have done this in the past but you have to be careful as a frequently occurring error will quickly flood an inbox :)

Of course if the error can be fixed by the user then you can just say so (and how to do so) in your message. That is about as thorough and fancy as you can get...