Hi, I'm sorry I have to ask this question again, but I haven't seen the exact answer to my problem or understood the answers... (?) I've got the following complaints from log4j : log4j:ERROR No appenders could be found for category (worm.gui.TimestamperGUI). log4j:ERROR Please initialize the log4j system properly. I've read from the "troubleshooting guide" this is because there's no appenders attached to my category or its ancestors. But I've done that ! My configuration file is : log4j.rootCategory=DEBUG,MyFileAppender,MyConsoleAppender [..Definition of MyFileAppender and MyConsoleAppender...] log4j.category.worm=DEBUG,MyFileAppender, MyConsoleAppender Isn't that last line attach worm category to my appenders ? If worm is an ancestor of worm.gui.TimestampGUI, this should be okay ? ------- Other maybe useful information : I'm passing my configuration file to the program through a system property : java ... -Dlog4j.conf.file="log.properties" worm.gui.TimestampGUI Then, in my application, I've got : package worm.gui; [...] import org.apache.log4j.Category; import org.apache.log4j.PropertyConfigurator; public class TimestampGUI { static Category cat = Category.getInstance(TimestamperGUI.class.getName()); [...] public static void main(String args[]){ cat.debug("--> main()"); try { // setting up trace file PropertyConfigurator.configure(System.getProperty("log4j.conf.file")); cat.info("Trace controller starts."); } catch(NullPointerException exp){ // no logging configuration file has been specified // we disable logging Category.getDefaultHierarchy().disableAll(); } } } Thanks for any explanation, I haven't understood other answers... Axelle. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]