Groups > comp.lang.java.programmer > #12356

Re: Aspect questions?

From	Lew <noone@lewscanon.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: Aspect questions?
Date	2012-02-26 00:21 -0800
Organization	albasani.net
Message-ID	<jicq2k$ifr$1@news.albasani.net> (permalink)
References	(6 earlier) <XnsA004B034AE631jpnasty@94.75.214.39> <4f496d47$0$289$14726298@news.sunsite.dk> <jicc1d$er6$1@dont-email.me> <jiciuf$458$1@news.albasani.net> <jicp1u$qos$1@dont-email.me>

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On 02/26/2012 12:04 AM, markspace wrote:
> On 2/25/2012 10:20 PM, Lew wrote:
>
>> markspace wrote:
>>> (Different customers of yours prefer different loggers.)
>
>> That's what Apache Commons logging is for.
>
>
> Back when I was playing with applets, I discovered by default that the jul
> logger creates a log file in your home directory. (There's a default
> logging.properties file created with every Java desktop installation and
> that's what it does). With unsigned applets, this means even trying to
> instantiate any part of the jul logging system will throw an exception,
> because the applet has no permissions for creating files.
>
> There might be ways around that, but it spooked me and I decided that since I
> didn't have direct control over a user's system, I couldn't rely on any
> defaults in the JRE installation. So I made a shell logging system that
> wrapped the jul logger and allowed me control, in case I had to use something
> besides jul entirely.
>
> BTW, I wasn't aware that Apache Commons logging was different than JULI/log4j.
> Thanks for pointing that out.
>
>
>>>
>>> This requires that a logger is instantiated for each object as it is
>>> created.
>
>> No, it doesn't.
>>
>> It only creates one per class.
>
>
> OK, assuming loggers are cached and reused, fair point.

It's not really a cache. The logger factory method is simply guaranteed to 
return the same instance of the same-identified logger, just as say 
'Integer.valueOf(5)' is guaranteed to return the same 'Integer' instance each 
time within the program.

<http://docs.oracle.com/javase/7/docs/api/java/util/logging/Logger.html#getLogger(java.lang.String)>
"Find or create a logger for a named subsystem. If a logger has already been 
created with the given name it is returned. Otherwise a new logger is created."

<http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Logger.html#getLogger(java.lang.String)>
"Retrieve a logger named according to the value of the name parameter. If the 
named logger already exists, then the existing instance will be returned. 
Otherwise, a new instance is created."

It's important to know what the system promises, and the Javadocs tell you.

The logging frameworks are foundational and should be part of the early 
education of the Java programmer, along with the collections framework. 
Knowledge of things like that all same-named loggers point to the same logger 
instance is useful.

>> Lazy initialization is waaay overrated.
>>
>> First prove you have an optimization problem before you present an
>> optimization solution.
>
>
> Well, that "optimization" is code that my IDE writes by default. It costs me
> nothing, so I'd rather prove that it's a problem before messing with it.

You mean the IDE generates lazy instantiation for you? It's a problem in that 
it is additional code that resists best-practice idioms without benefit. The 
fact that you have accepted someone else's default doesn't make it a great idea.

Your lazy acceptance of a lazy initialization idiom is not good for the code, 
however much it may appear to you to save you the minute to change your IDE's 
default to a saner approach.

I'm sensitive to habits, especially ones that lead to trouble. Maybe your 
classes by default aren't meant for concurrent programs, for example, but I 
never assume my classes won't be used that way. I also believe that if you 
practice safe idioms you don't accidentally forget to use one when you need it.

Lazy instantiation has proven dangers and it causes things to be initialized 
in an unpredictable way and out of the normal class sequence for eagerly 
initialized items.  Whether those dangers apply in this case or that case, it 
costs nothing to do things the safe way and not have to shift gears when you 
suspect danger.

>> If you really, really, really, really, really, really need to spawn a
>> thread to make logging faster, which you don't, you can do that over a
>> regular ju.logging or log4j call. You don't have to throw out the baby
>> with the bath water.
>
>
> I've never had to spawn threads for logging, and the idea was something I've
> only seen presented once, so I'm not sure how useful the concept is. However,
> I keep it in mind as something that might have to happen someday.

It was the idea you suggested, though.

I was just responding with a way to follow your suggestion, with which I 
disagree BTW, that didn't involve having to reinvent the whole logging 
framework thing.

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

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Thread

Aspect questions? Novice <novice@example..com> - 2012-02-24 20:10 +0000
  Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-24 13:05 -0800
    Re: Aspect questions? Novice <novice@example..com> - 2012-02-25 05:47 +0000
      Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-24 23:40 -0800
        Re: Aspect questions? Novice <novice@example..com> - 2012-02-25 17:02 +0000
          Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-25 12:08 -0800
            Re: Aspect questions? Novice <novice@example..com> - 2012-02-25 22:12 +0000
              Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-25 14:27 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-25 23:29 +0000
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-25 18:33 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-26 14:38 +0000
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 10:49 -0500
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 10:53 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-26 18:17 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-25 16:01 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-26 17:22 +0000
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 12:25 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-26 21:08 +0000
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 18:33 -0500
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 17:05 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 20:18 -0500
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 21:29 -0800
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-27 05:44 -0400
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-27 21:37 -0500
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-28 00:04 -0800
                Re: Aspect questions? Patricia Shanahan <pats@acm.org> - 2012-02-28 01:39 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-29 14:54 +0000
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-28 17:24 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 04:53 +0000
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-03-02 17:08 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 05:12 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 21:38 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 17:27 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-27 12:22 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 22:50 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-27 17:24 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-29 15:00 +0000
                Re: Aspect questions? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-02-29 09:14 -0800
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-29 09:55 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-29 21:31 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-29 23:06 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-02 04:33 +0000
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-04 23:00 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-03-04 17:07 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-05 15:33 +0000
                JavaDoc linking (Was: Aspect questions?) Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2012-03-05 08:38 -0800
                Re: JavaDoc linking (Was: Aspect questions?) Novice <novice@example..com> - 2012-03-05 17:40 +0000
                Re: JavaDoc linking (Was: Aspect questions?) Patricia Shanahan <pats@acm.org> - 2012-03-05 21:25 -0800
                Re: JavaDoc linking (Was: Aspect questions?) Arne Vajhøj <arne@vajhoej.dk> - 2012-03-06 17:23 -0500
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-03-05 23:45 -0800
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-03-06 06:03 -0400
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-03-06 21:05 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-03-02 17:11 -0500
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-03-02 17:09 -0500
                Re: Aspect questions? Martin Gregorie <martin@address-in-sig.invalid> - 2012-02-26 23:43 +0000
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 05:20 +0000
                Re: Aspect questions? Patricia Shanahan <pats@acm.org> - 2012-02-26 21:32 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 17:36 +0000
                Re: Aspect questions? Jeff Higgins <jeff@invalid.invalid> - 2012-02-27 13:18 -0500
                Re: Aspect questions? Jeff Higgins <jeff@invalid.invalid> - 2012-02-27 14:05 -0500
                Re: Aspect questions? Jeff Higgins <jeff@invalid.invalid> - 2012-02-27 14:33 -0500
                Re: Aspect questions? Jeff Higgins <jeff@invalid.invalid> - 2012-02-27 14:53 -0500
                Re: Aspect questions? Jeff Higgins <jeff@invalid.invalid> - 2012-02-27 15:16 -0500
                Re: Aspect questions? Jeff Higgins <jeff@invalid.invalid> - 2012-02-27 17:57 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 22:59 +0000
                Re: Aspect questions? Jeff Higgins <jeff@invalid.invalid> - 2012-02-28 05:50 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-29 15:03 +0000
                Re: Aspect questions? Patricia Shanahan <pats@acm.org> - 2012-02-27 13:17 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 22:55 +0000
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-27 05:58 -0400
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 18:14 +0000
                Re: Aspect questions? Martin Gregorie <martin@address-in-sig.invalid> - 2012-02-28 00:12 +0000
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-28 02:04 +0000
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-27 21:22 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-29 15:11 +0000
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-03-02 17:14 -0500
                Re: Aspect questions? Martin Gregorie <martin@address-in-sig.invalid> - 2012-02-28 23:09 +0000
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-29 15:25 +0000
                Re: Aspect questions? Martin Gregorie <martin@address-in-sig.invalid> - 2012-03-01 00:22 +0000
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-01 01:44 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-29 23:24 -0800
                Re: Aspect questions? Martin Gregorie <martin@address-in-sig.invalid> - 2012-03-01 21:19 +0000
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-02 01:52 +0000
                Re: Aspect questions? Martin Gregorie <martin@address-in-sig.invalid> - 2012-03-03 01:39 +0000
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-05 15:38 +0000
                Re: Aspect questions? Martin Gregorie <martin@address-in-sig.invalid> - 2012-03-05 22:50 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-03-05 23:46 -0800
                Re: Aspect questions? Patricia Shanahan <pats@acm.org> - 2012-03-06 08:14 -0800
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-03-06 21:23 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-03-08 20:10 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-02 01:49 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-03-01 22:38 -0800
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-03-02 06:05 -0400
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-02 14:25 +0000
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-03-02 18:10 -0400
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-02 14:12 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-03-02 08:57 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-05 15:57 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-03-05 23:48 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-03-07 20:33 +0000
                Re: Aspect questions? Lew <lewbloch@gmail.com> - 2012-03-07 13:09 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-03-02 17:20 -0500
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-03-02 14:28 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-03-02 17:16 -0500
                Re: Aspect questions? markspace <-@.> - 2012-02-26 10:10 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-26 20:52 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 13:48 -0800
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 13:47 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 18:40 -0500
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 18:36 -0500
                Re: Aspect questions? markspace <-@.> - 2012-02-26 16:04 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 19:38 -0500
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 17:09 -0800
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-26 20:08 -0400
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 19:43 -0500
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-27 22:03 -0400
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-27 21:18 -0500
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 13:43 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 01:11 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 21:49 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-27 18:37 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-27 12:28 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-28 00:55 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-27 17:37 -0800
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-29 15:57 +0000
                Re: Aspect questions? Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-02-28 03:21 -0600
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-28 09:19 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-27 21:12 -0500
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-28 05:59 -0400
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-28 17:27 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-29 16:07 +0000
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-03-02 17:26 -0500
              Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-25 18:22 -0500
                Re: Aspect questions? markspace <-@.> - 2012-02-25 20:22 -0800
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-25 22:20 -0800
                Re: Aspect questions? markspace <-@.> - 2012-02-26 00:04 -0800
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 00:21 -0800
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 00:33 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 10:43 -0500
                Re: Aspect questions? Martin Gregorie <martin@address-in-sig.invalid> - 2012-02-26 11:18 +0000
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-26 11:04 -0400
                Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-26 10:22 -0400
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-26 21:04 +0000
                Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-26 14:01 -0800
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 18:46 -0500
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 09:50 -0500
                Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-26 10:38 -0500
                Re: Aspect questions? Novice <novice@example..com> - 2012-02-26 20:49 +0000
      Re: Aspect questions? jlp <jlp@jlp.com> - 2012-02-25 09:47 +0100
        Re: Aspect questions? Novice <novice@example..com> - 2012-02-25 17:03 +0000
          Re: Aspect questions? jlp <jlp@jlp.com> - 2012-02-25 20:02 +0100
      Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-25 10:20 -0400
        Re: Aspect questions? markspace <-@.> - 2012-02-25 08:18 -0800
          Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-25 12:04 -0500
        Re: Aspect questions? Novice <novice@example..com> - 2012-02-25 17:17 +0000
          Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-25 18:40 -0400
          Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-25 18:18 -0500
      Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-25 09:21 -0500
      Re: Aspect questions? Roedy Green <see_website@mindprod.com.invalid> - 2012-02-25 14:35 -0800
  Re: Aspect questions? markspace <-@.> - 2012-02-24 14:30 -0800
    Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-24 19:47 -0500
      Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-24 20:52 -0800
        Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-25 09:31 -0500
        Re: Aspect questions? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-02-25 11:05 -0400
          Re: Aspect questions? Lew <noone@lewscanon.com> - 2012-02-25 12:20 -0800
  Re: Aspect questions? Arne Vajhøj <arne@vajhoej.dk> - 2012-02-24 19:00 -0500
  Re: Aspect questions? Tom Anderson <twic@urchin.earth.li> - 2012-02-25 00:22 +0000

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