On Thursday, Aug 14, 2003, at 13:34 Europe/London, Greg Wilkins wrote:
Jason Dillon wrote:[Exception] IllegalArgumentException: address must not be null+1
org.apache.geronimo.common.NullArgumentException extends IAE and handles the formatting of the message too, so you can:
throw new NullArgumentException("address");
I will only +1 the NullArgumentException if it is part of internationalizing
our Exception. So that NullArgumentException can print out:
There is no reason why it couldn't be internationalised, like any other Exception type. Indeed, there's a static factory method NullArgumentException("fieldName",field) to do just that.
I guess this could be as easily internationalised as uses of the IAE messages, but has the advantage that they're all in one place :-)
Other than that - I often find that subclassing exceptions just results it too extra hassle when too often most try blocks end with catch(Exception e) and you may as well just have one Exception type:
class ShitHappenedException extends Exception
True, but then that's bad client code as opposed to throwing specific types :-) But NAE is a subclass of IAE, so it's not expected to be caught on its own, just as part of a bad argument method (or more likely, RuntimeException.
I really think we ought to outlaw
try {} catch(Exception e) {
// stuff
}in the code -- it just eats too many exceptions that are desired (or at least, don't want to be hidden).
But I think subclassing exceptions is good, if it is to add functionality about throwing the exception (rather than catching it).
Bear in mind that as well as adding functionality, you're also subclassing the type. For example, EOFException is a subclass of IOException and adds no extra functionality, but it's a sufficiently common situation to be able to treat different exception types accordingly. When subclassing, you also subtype the superclass too ...
