In development scenarios where things can't be run in a debugger, or when you run the risk of masking the problem—logs are the greatest source of information about running a program. Pro Apache Log4j, Second Edition is the only Java Logging book available, and it includes best practices guidelines. Covered is the most recent release, version 1.2.9.
Step-by-step, the book explains core concepts, from basic to advanced. Code samples are in Java, and include guidelines for different application-specific needs. You'll also learn how to extend the API to write custom components. Furthermore, it describes best practices for using the feature-rich log4j API.