apache-commons-logging

What is the significance of log4j.rootLogger property in log4j.properties file? What happens if I don't use this property? Example : # 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 What happens if I set this property to ERROR mode. Samudra Gupta explains in his book 1 : The Logger object is the main object that an application developer uses to log any message. The Logger objects acting within a particular instance of an application follow a parent-child hierarchy .

Anybody has any idea what happened to my maven build? I am getting a lot of duplicate warnings. [WARNING] We have a duplicate org/apache/commons/logging/impl/LogFactoryImpl$1.class in /home/shengjie/.m2/repository/commons-logging/commons-logging-api/1.0.4/commons-logging-api-1.0.4.jar [WARNING] We have a duplicate org/apache/commons/logging/impl/LogFactoryImpl.class in /home/shengjie/.m2/repository/commons-logging/commons-logging-api/1.0.4/commons-logging-api-1.0.4.jar [WARNING] We have a duplicate org/apache/commons/logging/impl/NoOpLog.class in /home/shengjie/.m2/repository/commons-logging

Dave Syer (SpringSource) writes in his blog: Unfortunately, the worst thing about commons-logging, and what has made it unpopular with new tools, is also the runtime discovery algorithm. Why? What is the issue with its runtime discovery algorithm? Performance? Why? What is the issue with its runtime discovery algorithm? Performance? No, it's not performance, it's classloader pain . JCL discovery process relies on classloader hacks to find the logging framework at runtime but this mechanism leads to numerous problems including unexpected behavior, hard to debug classloading problems resulting

I am using apache.commons.logging, for now I wanted to use SimpleLog implementation, but when changed the level, loggers from libraries come out. I want it to turn it off. Is there a easy way to change log level for whole package (Can log4j do that) ? I have tried to set org.apache.commons.logging.simplelog.log.foo=fatal in simplelog property files to disable (setting to fatal is OK) foo logger, but it doesn't works. (foo is a name of logger that appears in output : [INFO] foo - Message). In Log4j you can specify a logging level for specified package, class or logger identified by string. You

I'm working on a simple desktop app (not webapp). Here is my log4j.properties : log4j.rootCategory=INFO, stdout log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %t %c{2}:%L $$$$ %m%n log4j.logger.org.springframework=ERROR,stdout As you can see, in order to eliminate Spring logging messages from the console, I tried this solution: Disabling Spring log, to have readable logs When I call log4j logger from my code, the logging messages are according to the pattern