On Sat, Feb 15, 2014 at 7:13 PM, [email protected] <[email protected]> wrote: > Hi devs, > > On > http://dev.xwiki.org/xwiki/bin/view/Community/JavaCodeStyle#HLoggingBestPractices > we have some best practices defined for logging. > > I'd like to propose some additions. > > Best practices: > > * Use SLF4J > * If you're in a component get the logger injected using @Inject private > Logger logger otherwise use: > private static final Logger LOGGER = LoggerFactory.getLogger(My.class); > * Use logger.info() when it's absolutely necessary for the user to see the > message in the logs. Usually only used at startup and we want to limit what > the user sees to the absolute necessary to avoid swamping him. > * Use logger.warning() when an error happens but it doesn't compromise the > stability and general working of an XWiki instance. A warning just shows the > user that something has gone wrong and it should provide him with as much > information as possible to solve the issue. Do not print a stack trace when > you output a warning since stack traces fill the logs and should be reserved > for errors. In the view of users stack traces are synonymous with errors. We > want it to be easy for admins to visually check the log files and see > important problems (ie errors). > * Use logger.error() when there's an important problem that compromises the > stability of the XWiki instance or that prevent an important system from > working and that should not have happened. Always pass a stack trace when > logging errors since it's something that shouldn't have happened an a > developer will need to debug the problem to fix it. > * Always log as much information as possible to make it easier to understand > what's going on. > * Surround parameters with "[]" in order to separate visually the text from > the parameters and also clearly notice when leading/trailing spaces are > located in parameters. > * For improved performances, always use the vararg signature of SLF4J for > logging parameters and do not concatenate them manually: > > this.logger.debug("Test message with [{}] and [{}]", param1, param2); > > vs > > this.logger.debug("Test message with [" + param1 + "] and [" + param2 + "]", > param1, param2); > > * When logging a warning, we don't want to log the full stack trace but it's > still interesting from time to time to display the root issue. If you do the > following you won't get the root issue: > > LOGGER.warn("Failed to determine if the index exists: [{}]. Trying to > recreate the index..", e.getMessage()); > > Instead use ExceptionUtils from commons lang: > > LOGGER.warn("Failed to determine if the index exists: [{}]. Trying to > recreate the index..", ExceptionUtils.getRootCauseMessage(e)); > > WDYT?
+1, I'll update my code :) Thanks, Marius > > Thanks > -Vincent > > > > > > > _______________________________________________ > devs mailing list > [email protected] > http://lists.xwiki.org/mailman/listinfo/devs _______________________________________________ devs mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/devs
