JOE should have a file appender per default

Current Situation

The JOE log is written to stdout only and is only visible when starting JOE with the debug option.

Desired Behavior

• The JOE log should always be written to a file
• The filename is ${SCHEDULER_DATA}/logs/JOE.log
• The default log level is error
• The log should be overwritten every time JOE starts
• The log also should be written to stdout
• To enable the debug log, the setting in JOE-log-4j.properties can be changed to
  log4j.rootLogger=debug, stdout, joe

The content of the file JOE-log-4j.properties is

log4j.rootLogger=error, stdout, joe

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=[%5p] (%F:%L) - %m%n

log4j.appender.joe=org.apache.log4j.FileAppender
log4j.appender.joe.Append=false
log4j.appender.joe.layout=org.apache.log4j.EnhancedPatternLayout
log4j.appender.joe.layout.ConversionPattern=%d{ISO8601}{Europe/Berlin} %c [%-5p] - %m%n
log4j.appender.joe.File=${SCHEDULER_DATA}/logs/JOE.log