What is log4j
log4j is a reliable, fast and flexible logging framework (APIs)
written in Java, which is
distributed under the Apache Software License.
log4j has been ported to the C, C++, C#, Perl, Python, Ruby, and
Eiffel languages.
log4j is highly configurable through external configuration
files at runtime. It views the
logging process in terms of levels of priorities and offers
mechanisms to direct logging
information
to a great variety of destinations.