[3205] in java-interest
Re: Better way to handle user-defined exception
daemon@ATHENA.MIT.EDU (Edith Au)
Thu Nov 2 22:01:14 1995
To: Thomas Ball <Thomas.Ball@Eng.Sun.COM>
Date: Thu, 2 Nov 1995 20:00:27 -0500 (EST)
From: Edith Au <edith@pencom.com>
Cc: java-interest@java.sun.com
In-Reply-To: <9511022352.AA17477@alapa.Eng.Sun.COM> from "Thomas Ball" at Nov 2, 95 03:52:12 pm
>
> > Let say if method1 calls method2 ....calls method5. I thought throwing
> > an exception in method5 and have method1 or method2 to catch it will make
> > method3, method4 's codes cleaner because they don't need to do anything
> > special in their codes.
>
> That's exactly right -- throw the exception where the problem is detected
> (method5), and then handle the exception where it's most appropriate
> (method1). You understand this better than you give yourself credit for.
>
> The only wrinkle the new compiler adds is that the intermediate methods
> need to declare that they can throw method5's exception, since they
> aren't dealing with that exception in any way:
>
> void method5(int x) throws OutOfRangeException {
> if (x > 10) {
> throw new OutOfRangeException("x = " + Integer.toString(x));
> }
> }
>
> void method2(int x) throws OutOfRangeException {
> method5(x);
> }
>
> void method1(int x) {
> try {
> method2(x);
> } catch (OutOfRangeException e) {
> System.out.println(e.toString());
> }
> }
OK. Now back to my original question. I still need a dummy exception,
OutOfRangeException which has no code at all because I don't want to show
user the thread stack (by calling super(mesg) in a constructor) and I would
like to have a separate method to handle the error message.
I might end up with something like
main()
{
try
{
....
....
}
catch (dummyException1 e)
{
printErrMesg("invalid ID. Please try again.");
...
}
catch (dummyException2 e)
{
printErrMesg("Please enter a whole number for the age field.");
....
}
catch (dummyException3 e)
{....}
.
.
.
There must be a better way to handle this. The reason why I insist
having printErrMesg to hanlde the error message is because I might want
to print error to System.in, to the status bar of a browser, to the network
stream, to a popup windows......
Any good suggestion?
Cheers,
Edith
=========================================================================
Edith Au Tel: (212) 513 7777
WWW Specialist Email: edith@pencom.com
Pencom Systems Incorporated WWW: http://www.pencomsi.com/~edith
40 Fulton Street,
NY, NY 10038
===============================================================================
-
This message was sent to the java-interest mailing list
Info: send 'help' to java-interest-request@java.sun.com
