Next we need to configure the Log4j library to our requirements. Log4j reads its configurations from log4j.properties file (or log4j.xml) placed in the CLASSPATH. Every log4j.properties file defines the following three things, mainly:
Quick Links for Java Programmers
(1) log4j Quick Reference Guide
A quick log4j reference guide for log4j Programmers.
(2) log4j Resources
A collection of log4j Sites, Books and Articles is given at this page.