More details would help in how to answer your questions. I will try to answer, but if you still have questions please provide more information.
How have you configured your log4j? Using a properties or xml file or programmatically? What kind of appender are you using?
How are you creating the Loggers?
Are you specifying the layout or using a default layout? The layout may be configured to include the date (%d) and name of the Logger (%c), see
log4j manual and
Java Documentation on PatternLayout.
If you're getting Loggers using Logger.getLogger(MyClass.class) or Logger.getLogger("com.foo.bar.MyClass"), the logger name is the fully qualified class name and that can be included using %c as mentioned above. If you're using some other naming convention for your loggers, then the documentation describes how to get the information, but it indicates the performance may be an issue.
[ April 13, 2005: Message edited by: Carol Enderlin ]