CODEWITHSUNDEEP
javarotationlog4j
eventhorizon
eventhorizon

Reputation: 3377

How to rotate a log4j log manually

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 - and if so: How?

Solved like this:

void rolloverLogs() {
    for(final Enumeration<?> loggers = LogManager.getCurrentLoggers(); loggers.hasMoreElements(); )  {

        final Logger logger = (Logger) loggers.nextElement();

        for (final Enumeration<?> appenders = logger.getAllAppenders(); appenders.hasMoreElements(); )  {

            final Appender a = (Appender) appenders.nextElement();

            if(!RollingFileAppender.class.isInstance(a))
                continue;

            ((RollingFileAppender)a).rollOver();
        }
    }
}

Upvotes: 3

Views: 4518

Answers (3)

rgoers
rgoers

Reputation: 9151

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();
    }
}

Upvotes: 5

Lahiru Chandima
Lahiru Chandima

Reputation: 24138

For log4j2, you can use following.

    org.apache.logging.log4j.Logger logManagerLogger = LogManager.getLogger();
    Map<String, org.apache.logging.log4j.core.Appender> appenders = ((org.apache.logging.log4j.core.Logger) logManagerLogger).getAppenders();
    appenders.forEach((appenderName, appender) -> {
        if (appender instanceof RollingFileAppender) {
            logger.info("Rolling over appender " + appenderName);
            ((RollingFileAppender) appender).getManager().rollover();
        }
    });

Upvotes: 3

Jan
Jan

Reputation: 13858

If you're keeping track of your appenders, you could call

https://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/RollingFileAppender.html#rollOver()

That should do it. I guess it's also possible to iterate through all appenders you can find starting from root level - just make sure you keep track of which appenders you already rolled.

Upvotes: 2

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