Log4j: xml configuration: category tag -

i learning log4j. have seen <category> tag in xml configuration file find nothing information it's subelements(children) , attributes.

could anyone, please, tell me, how use tag , it's parameters do? maybe there usefull link?

the answer is:

one of common requirement in java projects, using log4j logging, have different log files each module (or layer) in project. example, if have web application, may want log debug/info messages service layer service.log file , log messages presentation layer web-app.log file , on. simple achieve in log4j. log4j has concept called category using can classify package category , assign appender category alone.