Multiple file hosting in log4j

Question

I have to put the log information in two separate log files based on some state. How to do it. here is my logging.properties file

log4j.rootLogger=debug, stdout, R
log4j.appender.stdout=org.apache.log4j.RollingFileAppender
log4j.appender.stdout.File=${catalina.home}/logs/std.log
log4j.appender.stdout.MaxFileSize=200KB
log4j.appender.stdout.MaxBackupIndex=2
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d [%c] %p - %m%n


log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=${catalina.home}/logs/demo.log
log4j.appender.R.MaxFileSize=200KB
log4j.appender.R.MaxBackupIndex=2
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%d [%c] %p - %m%n

Answer 1

You can define multiple applications and assign java packages to applications. In the example below, all classes in com.mycorp.webwill be written to web.log at the level DEBUG, and classes in com.mycorp.dbwill be written to db.log at the level INFO.

log4j.rootLogger=debug, weblogger, dblogger

#Define which packages use which appenders
log4j.logger.com.mycorp.web=DEBUG,weblogger
log4j.logger.com.mycorp.db=INFO,dblogger

#Ensure the logs don't add to each other
log4j.additivity.com.mycorp.web=false
log4j.additivity.com.mycorp.db=false

#Define web appender
log4j.appender.weblogger=org.apache.log4j.DailyRollingFileAppender
log4j.appender.weblogger.File=/var/log/myapp/web.log
log4j.appender.weblogger.DatePattern='.'yyyy-MM-dd
log4j.appender.weblogger.Append=true
log4j.appender.weblogger.layout=org.apache.log4j.PatternLayout
log4j.appender.weblogger.layout.ConversionPattern=%d [%t] %-5p %c{1} - %m %n

#Define db appender
log4j.appender.dblogger=org.apache.log4j.DailyRollingFileAppender
log4j.appender.dblogger.File=/var/log/myapp/db.log
log4j.appender.dblogger.DatePattern='.'yyyy-MM-dd
log4j.appender.dblogger.Append=true
log4j.appender.dblogger.layout=org.apache.log4j.PatternLayout
log4j.appender.dblogger.layout.ConversionPattern=%d [%t] %-5p %c{1} - %m %n

Answer 2

Depending on your condition, you can capture different recorders.

Logger x = predicate() ? Logger.getLogger("wombat") : Logger.getLogger("other");

http://logging.apache.org/log4j/1.2/manual.html ( "wombat" .)

Answer 3

If you need another file for some registrar, you should write something like this:

log4j.logger.LOGGER_ONE=DEBUG, stdout
log4j.logger.LOGGER_TWO=WARN, R