RE: Designing Logging class

[Veerappan Saravanan]

Title: Designing Logging class

Reshma,

 

This is Van. The one problem that we are finding with using static utility class is that the entire product is cluttered with calls to this static logging class. You are essentially bounding logging to this class.

 

i.e, there are going to be calls like

Logger.debug(...)

Logger.error(...)

 

all over the system.

 

Instead, we are changing the approach, by hiding the implementing class by using factory classes. One way to do that is to have a LogFactory (a factory singleton object) that returns different logging classes. In this case, then the call to log an error will be

 

LogFactory.getLogger().debug(...)

 

In this approach you are hiding the implementation class completely.

 

-Van

 

-----Original Message-----
From: Reshma Badadhe [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, July 17, 2001 8:18 AM
To: '[EMAIL PROTECTED]'
Subject: Designing Logging class

Hi,
I am looking into the approach suggested by Van  i.e making logging a static utility class. I have a Logger class which is as follows:

public class Logger
{
        //this instance is used for logging to a Trace log
        static public Category traceCat = Category.getInstance("Trace" +                                          Logger.class.getName());

        //this instance is used for logging to an Error log
        static public Category errCat = Category.getInstance("Error" +                                          Logger.class.getName());

        static
        {
                PropertyConfigurator.configureAndWatch("xxx.cfg",60000);
        }

}

This class can be then used by other modules that want to log messages. But i have some million-dollar questions to ask u "Know-It-Alls" ;-)

#1) I want the appender corresponding to the traceCat instance to log only debug and info messages i.e in the Trace log.

PropertyConfigurator doesnt support filters. And i tried adding code to do so but failed.
So what options do i have?
#2) I thought of adding a Constructor to use the single instance approach. Will this help in logging messages to same logfile in an appserver environment ( message:  "Multiple JVMs writing to one log file"). For the same reason, i've used the static initializer to configure the logging environment. Does this approach have any flaws?

Thanks in advance.

resh