How do I set log4j level on the command line?

Question

I want to add some log.debug statements to a class I\'m working on, and I\'d like to see that in output when running the test. I\'d like to override the log4j properties on

Answer 1

Based on Thorbjørn Ravn Andersens suggestion I wrote some code that makes this work

Add the following early in the main method and it is now possible to set the log level from the comand line. This have been tested in a project of mine but I'm new to log4j and might have made some mistake. If so please correct me.

    Logger.getRootLogger().setLevel(Level.WARN);
    HashMap logLevels=new HashMap();
    logLevels.put("ALL",Level.ALL);
    logLevels.put("TRACE",Level.TRACE);
    logLevels.put("DEBUG",Level.DEBUG);
    logLevels.put("INFO",Level.INFO);
    logLevels.put("WARN",Level.WARN);
    logLevels.put("ERROR",Level.ERROR);
    logLevels.put("FATAL",Level.FATAL);
    logLevels.put("OFF",Level.OFF);
    for(String name:System.getProperties().stringPropertyNames()){
        String logger="log4j.logger.";
        if(name.startsWith(logger)){
            String loggerName=name.substring(logger.length());
            String loggerValue=System.getProperty(name);
            if(logLevels.containsKey(loggerValue))
                Logger.getLogger(loggerName).setLevel(logLevels.get(loggerValue));
            else
                Logger.getRootLogger().warn("unknown log4j logg level on comand line: "+loggerValue);
        }
    }