On Jul 15, 2012, at 7:13 AM, Ralph Goers wrote:
> On Jul 15, 2012, at 6:36 AM, Gary Gregory wrote:
>
>> Hi All:
>>
>> I've only now been able to take a peek at v2 in SVN so... sorry for the late
>> email but I feel better late than never.
>>
>> With log4j 1.2, my usage pattern is:
>>
>> logger.debug(String.format("This %s and that %d on this day %1$tm
>> %1$te,%1$tY", this, this.getThat(), this.getCalendar()));
>>
>> In 2.0, we have this example:
>>
>> logger.debug("Logging in user {} with id {}", user.getName(), user.getId());
>>
>> Why invent a new syntax when String.format is baked into the JRE?
>
> Because you are doing the string formatting whether the log event will be
> logged or not, which means your logger.debug should always be wrapped in an
> if isDebugEnabled. Also, the current syntax is compatible with SLF4J. See
> http://www.slf4j.org/faq.html#logging_performance.
>
> If you want to write your debug message the way you have shown there is
> nothing that says you can't. It will still work. However, as I recall Ceki
> ran tests that showed the Java text formatting is pretty slow. See
> http://bugzilla.slf4j.org/show_bug.cgi?id=116 for a nice discussion on this,
> and related topics.
>
> One other point. The String with placeholders is handled by
> ParamaterizedMessage. This class could either be extended or enhanced to
> support another syntax. If it is extended then that class would have to be
> used in the logging call such as
>
> logger.debug(new FormattedMessage("This %s and that %d on this day
> %1$tm %1$te,%1$tY", this, this.getThat(), this.getCalendar()));
>
> The advantage with the above is that, although a FormattedMessage is created
> every time the logger.debug statement is executed, it will defer the actual
> message formatting until the event is logged (i.e. the formatting won't
> happen if debug logging is disabled).
I should note that you wouldn't be able to add a new Class named
FormattedMessage as there is already an interface with that name.
Ralph
