On Thu, 19 Jul 2001, Jonathan Reichhold wrote:
> Actually I've got a thought on how to add in debug messages without recompiling.
>For a horrible hack say I've got a java class
> like:
>
> //Constants.java
> public class Constants{
> public static boolean isDebug(){return true;}
> }
>
> And in my main code I call:
> if(Constants.isDebug()) log(someNastyFunction());
>
> Now I could keep to versions of a class file generated from
> Constants.java (one which returns true, one with returns false)
> Replacing the class file Constants.class based upon my needs would
> effectively turn debugging on/off. There is an overhead of this
> approach for the lookup of the boolean, but it avoids the need to
> recompile to turn on debugging. It isn't as nice as having a debug
> flag passed in, but it would be a quick hack for most classes. It
> could even be used to debug code in "production" by replacing the
> class file and restarting. I prefer flags/config files to turn stuff
> like this on/off, but it is a relatively quick hack...
>
This hack definitely works. As long as you're willing to pay the overhead
for the method call, it's essentially equivalent to asking Log4J whether
or not debugging output is enabled, which does something similar (but asks
the instantiated logger object, instead of being a static method).
>
> Jonathan
>
Craig
> ----- Original Message -----
> From: "Pier P. Fumagalli" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Thursday, July 19, 2001 1:24 PM
> Subject: Re: [TC4.0] Disabling debug output...
>
>
> > Craig R. McClanahan at [EMAIL PROTECTED] wrote:
> > >
> > > - However, Pier's proposed approach doesn't deal with a need that I've
> > > experienced regularly -- the need to turn on debugging messages
> > > dynamically on an existing component, *without* recompiling it. This
> > > is NOT simply aesthetics; either you can or you cannot change the level
> > > of debugging output at runtime.
> >
> > You didn't get it Craig... I'm simply proposing to use the if (DEBUG)
> > approach _instead_ of commenting out logs in the source file...
> >
> > Go and look at HttpConnector.java... There are TONS of // (comments) that
> > could be replaced with an if (DEBUG).
> >
> > If you remove the comments, you too have to recompile the sources...
> >
> > Pier
> >
> >
>
>
