- save log4j.properties in /src folder, or in /src/main/resources for a Maven project. After building, it will end up in /bin. The goal is to have this file in the classpath
- Add log4j.jar to build path
Contents of log4j.properties
# Set root logger level to DEBUG and its only appender to A1.
log4j.rootLogger=DEBUG, A1
# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender
# A1 uses PatternLayout.
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%6r [%t] %-5p %c{1} - %m%n
log4j.logger.com.my.class=DEBUG
Add a file appender:
# FileAppender log4j.appender.FA=org.apache.log4j.RollingFileAppender log4j.appender.FA.layout=org.apache.log4j.PatternLayout log4j.appender.FA.layout.ConversionPattern=%6r %-5p %m%n log4j.appender.FA.File=/var/log/myapp.log # classes in package com.tnsi use INFO level # output is logged to FA log4j.logger.com=DEBUG
Root logger to console and a file appender only for com.my.class classes:
# Set root logger level to DEBUG and its only appender to A1.
log4j.rootLogger=DEBUG, A1
# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.NULL=org.apache.log4j.varia.NullAppender
# A1 uses PatternLayout.
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c{1}:%M - %m%n
log4j.appender.A1.Threshold=INFO
log4j.appender.F1=org.apache.log4j.RollingFileAppender
log4j.appender.F1.layout=org.apache.log4j.PatternLayout
log4j.appender.F1.layout.ConversionPattern=%m%n
log4j.appender.F1.File=/var/log/application.log
log4j.appender.F1.Threshold=DEBUG
log4j.logger.org.apache=INFO,NULL
log4j.logger.com.my.class=DEBUG,F1
