Advantage of log4j

Question

What\'s the advantage of log4j over set System.out and System.err to output to a log file?

Answer 1

log4j allows you to log to various resources e.g. event log, email, file system etc while allowing your application to remain decoupled from all of these resources. Furthermore, you get to use a common interface to log to all of the various resources without having to learn or integrate thier corresponding APIs.