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Posted to log4j-user@logging.apache.org by Yaakov Chaikin <ya...@gmail.com> on 2008/01/07 05:20:47 UTC

Name of the class showing up in logs

Hi,

I am using log4j 1.2.14.

I have a class where I've declared the logger as follows:
protected Logger logger = Logger.getLogger(SomeClass.class);

In one of the methods in that class, I pass the 'logger' to a static
method of another class, like this:
SomeOtherClass.doMethod(logger);

The output that I get is showing that the logging is coming from
SomeOtherClass instead of from SomeClass, which is strange to me. I've
been using log4j for a long time, but it's possible that I've never
noticed this before.

Is there a way to tell log4j to use the originally initialized class
instead of the one it's executing from? I am not even 100% how it
knows which class it's in. I was assuming that the logging is always
done from the class that it was initialized with. Am I configuring
something wrong?

My appender is configured as follows:

    <appender name="testing-stdout" class="org.apache.log4j.ConsoleAppender">
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern"
                value="***-> %-5p %C{1} - %m%n"/>
        </layout>
    </appender>


Any help would be appreciated.

Thanks,
Yaakov.

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Re: Name of the class showing up in logs

Posted by Yaakov Chaikin <ya...@gmail.com>.
Whoops! Thanks for pointing that out. It was a copying typo from my
previous projects. It's been a while since I actually looked in on
those rules.

Thanks,
Yaakov.

On Jan 7, 2008 12:32 AM, Jacob Kjome <ho...@visi.com> wrote:
>
>
> Yaakov Chaikin wrote:
> > Hi,
> >
> > I am using log4j 1.2.14.
> >
> > I have a class where I've declared the logger as follows:
> > protected Logger logger = Logger.getLogger(SomeClass.class);
> >
> > In one of the methods in that class, I pass the 'logger' to a static
> > method of another class, like this:
> > SomeOtherClass.doMethod(logger);
> >
> > The output that I get is showing that the logging is coming from
> > SomeOtherClass instead of from SomeClass, which is strange to me. I've
> > been using log4j for a long time, but it's possible that I've never
> > noticed this before.
> >
>
> I think you must be somehow confused.  Keep in mind that using FQCN of the class
> for the logger name is just a common convention.  A logger name is just an
> arbitrary String.  If you create a logger with a given name and you pass it to
> another method to use, it will use the name associated with that logger instance.
>   Log4j doesn't try to track the class the logging is coming from.  It just knows
> it's own logger name and uses it.  Whoops.  It's your PatternLayout.  Read more
> below...
>
> > Is there a way to tell log4j to use the originally initialized class
> > instead of the one it's executing from? I am not even 100% how it
> > knows which class it's in. I was assuming that the logging is always
> > done from the class that it was initialized with. Am I configuring
> > something wrong?
> >
> > My appender is configured as follows:
> >
> >     <appender name="testing-stdout" class="org.apache.log4j.ConsoleAppender">
> >         <layout class="org.apache.log4j.PatternLayout">
> >             <param name="ConversionPattern"
> >                 value="***-> %-5p %C{1} - %m%n"/>
> >         </layout>
> >     </appender>
> >
>
> Oh, well that explains it.  You aren't spitting out the category/logger name.
> You're spitting out the class name.  You should be using a lower-case "c", for
> "category", instead of "C", for "class".  When the pattern layout uses this, Log4j
> throws an exception and parses the stack trace for every log call.  I hope you
> aren't doing this in production!  Please read the Javadoc for PatternLayout [1].
> You probably want something like...
>
> <param name="ConversionPattern" value="***-> %-5p %c{1} - %m%n"/>
>
> [1] http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/PatternLayout.html
>
>
> Jake
>
> >
> > Any help would be appreciated.
> >
> > Thanks,
> > Yaakov.
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: log4j-user-unsubscribe@logging.apache.org
> > For additional commands, e-mail: log4j-user-help@logging.apache.org
> >
> >
> >
> >
>
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>
>

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Re: Name of the class showing up in logs

Posted by Jacob Kjome <ho...@visi.com>.

Yaakov Chaikin wrote:
> Hi,
> 
> I am using log4j 1.2.14.
> 
> I have a class where I've declared the logger as follows:
> protected Logger logger = Logger.getLogger(SomeClass.class);
> 
> In one of the methods in that class, I pass the 'logger' to a static
> method of another class, like this:
> SomeOtherClass.doMethod(logger);
> 
> The output that I get is showing that the logging is coming from
> SomeOtherClass instead of from SomeClass, which is strange to me. I've
> been using log4j for a long time, but it's possible that I've never
> noticed this before.
> 

I think you must be somehow confused.  Keep in mind that using FQCN of the class 
for the logger name is just a common convention.  A logger name is just an 
arbitrary String.  If you create a logger with a given name and you pass it to 
another method to use, it will use the name associated with that logger instance. 
  Log4j doesn't try to track the class the logging is coming from.  It just knows 
it's own logger name and uses it.  Whoops.  It's your PatternLayout.  Read more 
below...

> Is there a way to tell log4j to use the originally initialized class
> instead of the one it's executing from? I am not even 100% how it
> knows which class it's in. I was assuming that the logging is always
> done from the class that it was initialized with. Am I configuring
> something wrong?
> 
> My appender is configured as follows:
> 
>     <appender name="testing-stdout" class="org.apache.log4j.ConsoleAppender">
>         <layout class="org.apache.log4j.PatternLayout">
>             <param name="ConversionPattern"
>                 value="***-> %-5p %C{1} - %m%n"/>
>         </layout>
>     </appender>
> 

Oh, well that explains it.  You aren't spitting out the category/logger name. 
You're spitting out the class name.  You should be using a lower-case "c", for 
"category", instead of "C", for "class".  When the pattern layout uses this, Log4j 
throws an exception and parses the stack trace for every log call.  I hope you 
aren't doing this in production!  Please read the Javadoc for PatternLayout [1]. 
You probably want something like...

<param name="ConversionPattern" value="***-> %-5p %c{1} - %m%n"/>

[1] http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/PatternLayout.html


Jake

> 
> Any help would be appreciated.
> 
> Thanks,
> Yaakov.
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: log4j-user-unsubscribe@logging.apache.org
> For additional commands, e-mail: log4j-user-help@logging.apache.org
> 
> 
> 
> 

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