[logback-user] Filtering stacktraces by evaluating packages

[Christopher BROWN]

Hi Robert,

Thanks, I'll bookmark this.  Having said that, I suspect there's a simpler
way using EventEvaluator but I can't see how to wire that up to the
exception conversion handler.  Simpler meaning here "installing one class
as opposed to wrapping up many classes", or "one extra line of Java code
and a little class to go along with it".

Also, if I understand your code correctly, it filters frames (e.g.: if
there's a frame in the middle of the stack with
org.codehaus.groovy.runtime.*, it gets dropped without necessarily
affecting frames higher up or lower down), whereas the EventEvaluator acts
as a cut-off ("don't go any further down").

Even if it's not exactly what I was looking for, I can see other cases
where I could apply what you've suggested, so thanks again!

--
Christopher


On 5 December 2011 14:33, Robert Elliot <rob at lidalia.org.uk> wrote:

> I've done something very similar to this here:
> https://github.com/Mahoney/lidalia-logging/
>
> Basically using the decorator pattern around Events.
>
> Specifically look at EventTransformingAppender and StackTraceCleanser, and
> have a look at src/main/resources/logback.xml to see how to configure it.
>  It's currently very specific to getting rid of Groovy noise, but it would
> be trivial to generalise it to get rid of other frames.
>
>
>
> ----- Original Message -----
> > From: "Christopher BROWN" <brown at reflexe.fr>
> > To: "LogBack Users list" <logback-user at qos.ch>
> > Sent: Monday, 5 December, 2011 11:44:25 AM
> > Subject: [logback-user] Filtering stacktraces by evaluating packages
> > Hello,
> >
> >
> > I would like to simplify stacktraces when errors occur in an
> > application. For example, with a hypothetical stack such as:
> >
> >
> >
> >
> > com.xyz.Wombat.doSomething
> > javax.servlet.http.HttpServlet.service
> > org.appserver.JspCompiler.handleJsp
> > org.appserver.ServletEngine.handleServlet
> > java.lang.Thread.run
> >
> >
> > ...going down from top-to-bottom, I'd like to detect that line
> > "org.appserver.JspCompiler.handleJsp" has been found, and exclude it
> > -- and all subsequent "lower down" stack frames -- from logging
> > output.
> >
> >
> > Looking at http://logback.qos.ch/manual/layouts.html#Evaluators I
> > assume it must be possible with EventEvaluator because of the syntax
> > %xEx{evaluator-n} but I can't find an example. Furthermore, as I set
> > up LogBack programmatically (and not via XML or any of bundled
> > "configurator"), I'd be happiest if I could be directed towards an
> > API-based example.
> >
> >
> > If it's of any use, here are two methods extracted from the class that
> > I use to configure LogBack (incomplete but should help see what I'm
> > trying to do, and how):
> >
> >
> >
> > private synchronized boolean maybeInitialize(final Logger logger,
> > String pattern)
> > {
> > // will throw ClassCastException if our configuration is incorrect (or
> > accessed from wrong classloader)
> > // that's OK, it's what should happen...
> > final ch.qos.logback.classic.Logger impl =
> > (ch.qos.logback.classic.Logger)logger;
> >
> >
> > // if there's an appender, then the logger seems to have been
> > configured
> > Iterator<Appender<ILoggingEvent>> it = impl.iteratorForAppenders();
> > if (it.hasNext())
> > {
> > return false;
> > }
> >
> >
> > String logFileName = impl.getName();
> > if (logFileName.startsWith(LOG_FILE_STDPREFIX) && logFileName.length()
> > > LOG_FILE_STDPREFIX.length())
> > {
> > logFileName = logFileName.substring(LOG_FILE_STDPREFIX.length());
> > }
> > logFileName += LOG_FILE_EXTENSION;
> >
> >
> > Appender<ILoggingEvent> appender;
> > if (CONFIG_VALUE_ROLL_TYPE_DATE.equals(_rollType))
> > {
> > appender = createRollByDateFileAppender(logFileName, pattern != null ?
> > pattern : PATTERN_FOR_DATE);
> > }
> > else if (CONFIG_VALUE_ROLL_TYPE_SIZE.equals(_rollType))
> > {
> > appender = createRollBySizeFileAppender(logFileName, pattern);
> > }
> > else
> > {
> > appender = createFileAppender(logFileName, pattern);
> > }
> >
> >
> > appender.start();
> >
> >
> > impl.addAppender(appender);
> > impl.setLevel(_level);
> > impl.setAdditive(false);
> >
> >
> > return true;
> > }
> >
> >
> >
> > private synchronized boolean maybeInitialize(final Logger logger,
> > String pattern)
> > {
> > // will throw ClassCastException if our configuration is incorrect (or
> > accessed from wrong classloader)
> > // that's OK, it's what should happen...
> > final ch.qos.logback.classic.Logger impl =
> > (ch.qos.logback.classic.Logger)logger;
> >
> >
> > // if there's an appender, then the logger seems to have been
> > configured
> > Iterator<Appender<ILoggingEvent>> it = impl.iteratorForAppenders();
> > if (it.hasNext())
> > {
> > return false;
> > }
> >
> >
> > String logFileName = impl.getName();
> > if (logFileName.startsWith(LOG_FILE_STDPREFIX) && logFileName.length()
> > > LOG_FILE_STDPREFIX.length())
> > {
> > logFileName = logFileName.substring(LOG_FILE_STDPREFIX.length());
> > }
> > logFileName += LOG_FILE_EXTENSION;
> >
> >
> > Appender<ILoggingEvent> appender;
> > if (CONFIG_VALUE_ROLL_TYPE_DATE.equals(_rollType))
> > {
> > appender = createRollByDateFileAppender(logFileName, pattern != null ?
> > pattern : PATTERN_FOR_DATE);
> > }
> > else if (CONFIG_VALUE_ROLL_TYPE_SIZE.equals(_rollType))
> > {
> > appender = createRollBySizeFileAppender(logFileName, pattern);
> > }
> > else
> > {
> > appender = createFileAppender(logFileName, pattern);
> > }
> >
> >
> > appender.start();
> >
> >
> > impl.addAppender(appender);
> > impl.setLevel(_level);
> > impl.setAdditive(false);
> >
> >
> > return true;
> > }
> >
> >
> >
> > Thanks,
> > Christopher
> >
> > _______________________________________________
> > Logback-user mailing list
> > Logback-user at qos.ch
> > http://mailman.qos.ch/mailman/listinfo/logback-user
> _______________________________________________
> Logback-user mailing list
> Logback-user at qos.ch
> http://mailman.qos.ch/mailman/listinfo/logback-user
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qos.ch/pipermail/logback-user/attachments/20111205/867c68f3/attachment-0001.html>