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From: Niclas Hedhman <niclas@hedhman.org>
Organization: Independent
To: "Apache Directory Developers List" <dev@directory.apache.org>
Subject: Re: [OT] How best to respond to null arguments?
Date: Fri, 2 Sep 2005 01:38:13 +0800
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On Friday 02 September 2005 00:35, Emmanuel Lecharny wrote:
> Using a good pattern in conjonction with slf4j could help a lot :
>
> if (arg =3D=3D null)
> =C2=A0 =C2=A0 {
> =C2=A0 =C2=A0 log.error("the third parameter ('history') is null");
> =C2=A0 =C2=A0 throw new IAE(<a message>);
> =C2=A0 =C2=A0 }
> ...
>
> As you can exhibit the method name and the line number with %C and %L,
> it increases the message correctness.

Very true, and my idea is to have a small utility that does the "trick" tha=
t=20
Log4J does, i.e. fill in the stack, grab the second top element for "where=
=20
was this detected" and the next element for "where was that called from"...

The other thing, personally(!), I don't think any "library" (definition of=
=20
what makes a library is a different story) should utilize logging framework=
s=20
at all, be very conservative with any external output and instead rely on=20
exceptions and events to communicate such things. For instance, pass all su=
ch=20
"log data" to a router class, where the user can register one or more Logge=
rs=20
if she wants it.

Cheers
Niclas