[
https://issues.apache.org/jira/browse/LOG4J2-491?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13864781#comment-13864781
]
Remko Popma commented on LOG4J2-491:
------------------------------------
It would be difficult to design such callbacks in a way that satisfies
everybody's potential needs: callback before/after the existing header/footer,
and you also mentioned you wanted your header to have the pattern layout
{{2014-01-07 15:07:56,700 INFO [Thread] }} prefix...
To be honest, this seems like a lot of work to accomplish something for which
you already have a solution (LOG4J2-486).
> RollingFile Appender - callbacks when rolling
> ----------------------------------------------
>
> Key: LOG4J2-491
> URL: https://issues.apache.org/jira/browse/LOG4J2-491
> Project: Log4j 2
> Issue Type: Wish
> Components: Appenders
> Affects Versions: 2.0-beta9
> Environment: Java 1.7, Linux
> Reporter: Joe Merten
>
> I want this callbacks to add some custom info at the top of each logfile,
> like the version string of my application, the application uptime and the
> system uptime. And even writing some »bye, bye / eof« to the bottom of the
> just closed logfile would also be fine.
> See also:
> * [LOG4J2-486]
> *
> [http://stackoverflow.com/questions/20819376/log4j2-rollingfile-appender-add-custom-info-at-the-start-of-each-logfile]
> Currently I need to extend DefaultRolloverStrategy and wrap around
> RolloverDescription and appender.rolling.helper.Action to place my code
> (and therefore I also have to copy some factory code of
> DefaultRolloverStrategy to support all config parameters etc.). Ok, this
> approach currently works but it needs ~150 lines of code and is
> maintenance-unfriendly eg. if DefaultRolloverStrategy gets more config
> parameters in future versions.
> The callbacks should provide at least the filename of the related logfile.
> An access to the configured Layout of the related appender would also
> helpful, so that the custom info could be correctly formatted (e.g. incl.
> timestamp or matching for xml etc.).
> I think there sould be 2 callbacks
> * 1st one for after all outstanding writes to the old logfile has been done
> (so thet I could add some stuff to the end of the old file), but before
> things like compressing are performed
> * 2nd one for to write my stuff to the top of the new logfile
> Ok, there must be take care of Layout.getHeader/Footer() (which is used by
> e.g. XMLLayout) considering if the callbacks should be called e.g. "inside or
> outside of the xml root tags".
> If I want to add my custom info as a kind of LogEvents, then the callbacks
> should be called before writing the Layout.getFooter() and after writing
> Layout.getHeader() to the file.
> But if someone want to add custom info outside of the xml root tags (e.g.
> someone might calculate a checksum over the logfile and write that to the
> very last line of the file) then the callbacks must be called outside
> header/footer.
> For my current needs, I require the callbacks inside of header/footer
> (although it not really matters for me while I currently only using
> PatternLayout).
> Bug finally that looks that we need callbacks for both cases.
--
This message was sent by Atlassian JIRA
(v6.1.5#6160)
---------------------------------------------------------------------
To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org
For additional commands, e-mail: log4j-dev-h...@logging.apache.org
