log4j-core/src/test/resources/AsyncLoggerTimestampMessageTest.xml

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="ERROR">
  <Appenders>
    <RandomAccessFile name="RandomAccessFile" fileName="target/AsyncLoggerTimestampMessageTest.log"
	    		immediateFlush="false" append="false">
      <PatternLayout>
        <Pattern>%d{UNIX_MILLIS} %m%n</Pattern>
      </PatternLayout>
    </RandomAccessFile>
  </Appenders>
  
  <Loggers>
    <Root level="info" includeLocation="false">
      <AppenderRef ref="RandomAccessFile"/>
    </Root>
  </Loggers>
</Configuration>