Re: Serializable Logging implementation

[Spiegs]

What is the best approach for someone starting a new app? Is having all 
of your model objects contain a transient static log instance, implement 
Serializable, and implement HttpSessionActivationListener to 
reinstantiate the log instance the best approach? What other approaches 
would you recommend if you were to start with a clean slate?

If you were to put the above code into a superclass, doesn't that go 
against the previously discussed advice of having the log instance 
belong to each class?

Thanks,
Eric
-------- Original Message ------
Subject:
Re: Serializable Logging implementation
From:
Tim Funk <[EMAIL PROTECTED]>
Date:
Wed, 15 Sep 2004 09:20:06 -0400
To:
Tomcat Users List <[EMAIL PROTECTED]>
Your NPE comes from the transient value not being restored from 
de-serialization.

Your best chance at this point without a lot of code changes is to
1) Make your log variable transient
2) Make your base class implement HttpSessionActivationListener.
3) Make your implementation of sessionDidActivate():
public void sessionDidActivate(HttpSessionEvent se) {
 if (log==null)
   log = LogFactory.getLog(this.getClass());
}
public void sessionWillPassivate (HttpSessionEvent se) {
 ; /* Nothing to do */
}
-Tim
Antony Paul wrote:
Then it throws NullPointerException
rgds
Antony Paul
----- Original Message -----
From: "Shapira, Yoav" <[EMAIL PROTECTED]>
To: "Tomcat Users List" <[EMAIL PROTECTED]>
Sent: Wednesday, September 15, 2004 6:05 PM
Subject: RE: Serializable Logging implementation

Hi,
Hmm, you want to be careful with this pattern.  I like the private
static one for Loggers -- there are very good reasons it's the
recommended pattern (by log4j, by the java.util.logging folks) and the
one that's used (by Tomcat and most other serious apps I know of).
If you really want to stick with your "base class gets the logger"
pattern, consider marking it as transient.
Yoav Shapira
Millennium Research Informatics

-----Original Message-----
From: Antony Paul [mailto:[EMAIL PROTECTED]
Sent: Wednesday, September 15, 2004 8:27 AM
To: Tomcat Users List
Subject: Re: Serializable Logging implementation
I extend a base form which gets the Log as
LogFactory.getLog(this.getClass());
So that no need to define and get a Log instance in subclass. Is there

any
way so that I can follow this pattern.
rgds
Antony Paul
----- Original Message -----
From: "Tim Funk" <[EMAIL PROTECTED]>
To: "Tomcat Users List" <[EMAIL PROTECTED]>
Sent: Wednesday, September 15, 2004 4:38 PM
Subject: Re: Serializable Logging implementation

logging instances should be static to the class.
// Commons logging example but a log4j equiv should be easy to find
    private static Log log = LogFactory.getLog(MyClass.class);
-Tim
Antony Paul wrote:

Hi,
   I used Log4J and commons logging in an ActionForm which is

stored
in
the
session. When I reload the context it is invalidating the session

because it
is non serializable. Is there any work around for this ?. Or do I

have
to
use any other Logger.