log4j in grails: error printed when use variable in appender config

Question

I am using slf4j \"DailyRollingFileAppender\" in grails 2.3.4.

When i tried to use a variable as part of the \"file\" parameter, the grails always print some error logs

Answer 1

Use Holders to read config properties. I assume it will not be able to read the config property itself while setting up log4j as it is part of the config itself.

import grails.util.Holders

...

log4j = {
// Example of changing the log pattern for the default console appender:
    appenders {
        console name: 'stdout', layout: pattern(conversionPattern: '%c{2} %m%n')
        appender new DailyRollingFileAppender(
            name: "userEventLog",
            file: "${Holders.config.event.log.dir}/user-event.log",
            layout: pattern(conversionPattern: '%m%n'),
            datePattern: "'.'yyyy_MM_dd",
            threshold: org.apache.log4j.Level.INFO
        )
    }

    info userEventLog: "app.bean.log.UserEventLog"
}