How do I make log4j create log files on demand only?

Question

We have a modular application where modules have their own log4j logs (i.e. communication log and error log). The appenders and categories for these are all configured in th

Answer 1

The file appenders have no option to lazily create the log files - the setFile method automatically creates the file if it doesn't already exist: ostream = new FileOutputStream(fileName, append);

You'll have to extend the appender and overwrite the file initialisation code yourself to get the behaviour you're after.