loading log4j.properties

String resource = "/log4j.properties"; // / is necessary
URL configFileResource = Log4JTest.class.getResource(resource);
PropertyConfigurator.configure(configFileResource);

log4j.properties

#default one
log4j.rootLogger=DEBUG, A1
log4j.appender.A1=org.apache.log4j.ConsoleAppender

log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%p [%t] %c{2} (%M:%L) - %m%n


#under package example
log4j.logger.example=INFO, A2

log4j.appender.A2=org.apache.log4j.FileAppender
log4j.appender.A2.File=${user.home}/test.txt

log4j.appender.A2.layout=org.apache.log4j.PatternLayout
log4j.appender.A2.layout.ConversionPattern=%5r %-5p [%t] %c{2} - %m%n