log4j vs logback [closed]

We are using log4j behind a selfmade wrapper. We plan to use much more features of it now.

Should we update to logback ?

(I mean the framework not a facade like SLF4J)

Logback natively implements the SLF4J API. This means that if you are using logback, you are actually using the SLF4J API. You could theoretically use the internals of the logback API directly for logging, but that is highly discouraged. All logback documentation and examples on loggers are written in terms of the SLF4J API.

So by using logback, you'd be actually using SLF4J and if for any reason you wanted to switch back to log4j, you could do so within minutes by simply dropping slf4j-log4j12.jar onto your class path.

When migrating from logback to log4j, logback specific parts, specifically those contained in logback.xml configuration file would still need to be migrated to its log4j equivalent, i.e. log4j.properties. When migrating in the other direction, log4j configuration, i.e. log4j.properties, would need to be converted to its logback equivalent. There is an on-line tool for that. The amount of work involved in migrating configuration files is much less than the work required to migrate logger calls disseminated throughout all your software's source code and its dependencies.

Should you? Yes.

Why? Log4J has essentially been deprecated by Logback.

Is it urgent? Maybe not.

Is it painless? Probably, but it may depend on your logging statements.

Note that if you really want to take full advantage of LogBack (or SLF4J), then you really need to write proper logging statements. This will yield advantages like faster code because of the lazy evaluation, and less lines of code because you can avoid guards.

Finally, I highly recommend SLF4J. (Why recreate the wheel with your own facade?)