java - How can I access the configured Log4J appenders at runtime?

Question

I want to configure an appender at startup and then dynamically add and remove it from various loggers on demand. I'd prefer to have log4j configure this appender itself, and just grab a reference to it when needed. If that's not possible, I'll have to instantiate the appender myself and hold onto it.

Answer 1

Appenders are generally added to the root logger. Here's some pseudocode

// get the root logger and remove the appender we want
Logger logger = Logger.getRootLogger();
Appender appender = logger.getAppender("foo");
logger.removeAppender(appender)

// when we want to add it back...
logger.addAppender(appender);

I'm pretty sure you can do this on other loggers than the root logger as well, though I've never tried that.