Java-based logging utility. It is used as standard logger nowadays. Log4j allows logging on class-by-class basis i.e., each class can be covered. Through Log4j we can turn on or off the logging at runtime by changing the configuration file.
|Ceki Gülcü, Apache Software Foundation
|Latest stable version
Log4j has certainly various advantages over System.out.println firstly being checking the output the sout outputs to standard output which is mostly a console window whereas the output from Log4j can be to the console or email server,database table or a log file.