Re: Aspect questions?

From:

Lew <noone@lewscanon.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 26 Feb 2012 17:09:19 -0800

Message-ID:

<jiel3t$tk3$3@news.albasani.net>

Arne Vajh??j wrote:

markspace wrote:

Arne Vajh??j wrote:

markspace wrote:

<http://commons.apache.org/logging/guide.html#Developing%20With%20JCL>

This section points out that it's more efficient to use "static" for the
logger. In desktop apps, that's what I'm used to seeing. However it also
says that "static" interacts poorly with JEE classloaders, so using
instance variables is the norm in JEE (and w/ Tomcat too).

What does "interacts poorly with JEE classloaders" mean??

Did anybody read the link?

How about you summarize the answer for us, as a courtesy.

Please?

"Note that for application code, declaring the log member as "static" is
more efficient as one Log object is created per class, and is
recommended.

But there is also just one Log object with a non-static ref??

However this is not safe to do for a class which may be
deployed via a "shared" classloader in a servlet or j2ee container or
similar environment. If the class may end up invoked with different
thread-context-classloader values set then the member must not be
declared static. The use of "static" should therefore be avoided in code
within any "library" type project. "

If the parent classloader of those classloaders is the
one that loads log4j, then you will end up with one
log object no matter what.

If log4j is loaded by those classloaders, then you will
end up with duplicate log objects no matter what you do.

So I still don't understand what the heck they are talking
about.

I'm with Arne on this one. How is having only one logger object per class more
efficient than having one logger object per class?

And you ignored Arne's question: 'What does "interacts poorly with JEE
classloaders" mean??'

--
Lew
Honi soit qui mal y pense.
http://upload.wikimedia.org/wikipedia/commons/c/cf/Friz.jpg