*Download log4j (apache-log4j-1.2.15.zip) from its download site
*Unzip
*Place log4j-1.2.8.jar in classpath
*Create a log4j.properties in classpath
log4j.rootLogger=debug, stdout, R
# Specify which package to log
log4j.logger.com.my.pkg=INFO, R
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
# Pattern to output the caller's file name and line number.
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=example.log
log4j.appender.R.MaxFileSize=100KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
# Print only messages of level WARN or above in the package com.foo.
log4j.logger.com.foo=WARN*Usage
import org.apache.log4j.*; public class TestClass extends TestCase { Logger log = Logger.getLogger(TestClass .class.getName()); public void testOne() { log.debug("Testing..."); }
* Specify log4j.properties. Defaults to log4j.properties
-Dlog4j.configuration=mylog4j.properties