Hi: Thanks for the replies. I am planning to use the .properties file internal to my .jar file (not using log4j default configuration).

Also, as suggested below, I plan to write a config utility class with static method. It is in this class I plan to use PropertyConfigurator class

However, instead of user invoking explicit API to configure with the library provided logging .properties file, I would still like to decide automatically when to use it. I would like to configure my library using this internal .properties file when no other logging has been configured. That's the use case which suits my library.

From another user's e-mail, there is a thread talking about detecting if log4j is configured - is that advisable for a library?

But from your mail - I am now sure of one thing. If by mistake, log4j is configured a second time inside the library, the user's root logger and other loggers would lose the settings from configuring the first time.

Is this a correct conclusion?

Thanks for all the replies...

Regards -Somesh

At 05:33 PM 6/3/2004 -0400, you wrote:

Sure. You can use a properties file or XML file

Bad idea. Logging is for your users, not for you (unless you are *using* your library, of course)

Exactly! You can't know what your users want to log and if you provide a default log4j.properties file in the classpath, then you may end up overriding a users own properties file causing the user excessive confusion as to why Log4j isn't logging the way they have it configured.

This is an even worse idea than providing a properties file which *might* override a users. In this case, you are programmatically configuring Log4j and will almost certainly override a users logging configuration, again,

causing excessive confusion for the user.

If you want a compromise, you could maybe provide a default log4j.properties file, but don't put it in the root of the jar where Log4j is looking for it. Then provide a utility class with a static method such as Log4jUtility.configureMyLibrary() which the user can call, if desired. configureMyLibrary() would load up your properties file and programmatically configure Log4j. Since this will be used only with the

user's clear intent, then there should be no confusion, keeping everyone happy.

The simple truth is that you shouldn't force your own concept of what you want logged upon your users. If users want to see logging from your app, they can specify your package to be logged (as long as you stick to the standard naming conventions for loggers, eg.... "com.mypackage.MyClass").

Reference the name of a system property and make sure to provide that system property either programmatically (before any configuration of Log4j happens) or via the command line such as:

java -Dlog_location=/path/to/log/directory MyClass

In the config file, have something like...

${log_location}/mylog.log

I hope I helped!

Jake