How to rotate a log4j log manually

Question

I have log4j configured to rotate the log every day.

In special situations I would like to trigger an additional log rotation manually.

Is this possible - an

Answer 1

The technique shown by Lahiru will only locate Appenders configured for a specific Logger which is based on the class the code resides in. The exact Appender(s) located may may vary if the configuration changes.

If you know the Appender name the best way to do this is:

org.apache.logging.log4j.core.LoggerContext context = LogManager.getContext(false);
Appender appender = context.getConfiguration().getAppender(appenderName);
if (appender instanceof RollingFileAppender) {
    ((RollingFileAppender) appender).getManager().rollover();
}

If you want to roll over all RollingFileAppenders you could do:

org.apache.logging.log4j.core.LoggerContext context = (org.apache.logging.log4j.core.LoggerContext) LogManager.getContext(false);
for (Appender appender : context.getConfiguration().getAppenders().values()) {
    if (appender instanceof RollingFileAppender) {
        ((RollingFileAppender) appender).getManager().rollover();
    }
}