Emmanuel Bourg <[EMAIL PROTECTED]> wrote on 01/19/2005 06:16:35 AM:
> 9. Logging entry/exit event is not so common and I'd better write
directly:
>
> log.debug("Entering MyClass.foo(" + param1 + ", " + param2 + ")");
>
> rather than
>
> log.enter(this, "foo", new Object[] { param1, param2 }, "Entering");
>
> enter()/exit() doesn't make the code much shorter, it provides just a
> more detailed semantic.
1. But more than just an alternate to debug. For loggers that "support"
it, it would be mapped to a different logging level [i.e. JSR-47 "FINER"].
If we were to follow the guidelines described in the current JCL users
guide for "debug" level logging, and map those over to include the
entry/exit method "level", then best practices for JCL would be:
a) log.debug() to be used as we cross component
boundries, allowing a high-level
view of the flow between multiple
components. Also reasonable to
log "interesting" events/information
that are meaningfull at a
component level.
b) log.entry/exit() would be used as we cross
class and method boundries,
allowing a view of the flow
between and within classes
within a component.
c) log.trace() would be used to provide additional
detail reflecting flow and information
within a method.
And by having these on separate levels [for those impls
that support the levels], you could enable
(a), (a)+(b), or (a)+(b)+(c).
2. Just FYI, the [conceptual] equivalent to
log.debug("Entering MyClass.foo(" + param1 + ", " + param2 + ")");
would be
log.enter(this, "foo", new Object[] { param1, param2 }, null);
Specifically,
Log.enter(Class clazz,
String method,
Object[] params,
String additionalText)
is intended to be mapped to the logger, and it is expected that the logger
impl would express that as something similar to:
"Entering " + clazz.getName() + "." + methodName + "(" + params + ") "
+ additionalText
[please consider that psuedo-code... there are details missing I know :-)]
> Emmanuel Bourg
*******************************************
Richard A. Sitze
IBM WebSphere WebServices Development
