When I investigated logging on android I came to the conclusion that the only usable logging that can be done in android is with the implementation that Google provides. I have no problem creating a Log4J jar for android but I am not willing to not support Java 9 to do it.
Ralph > On Jul 9, 2017, at 10:29 AM, Gary Gregory <[email protected]> wrote: > > But there is a file system on Android... > >> On Jul 9, 2017 10:15, "Matt Sicker" <[email protected]> wrote: >> >> It does seem that the problem is indeed only with log4j-api. While an >> Android developer might have some setup to get logging working during >> development, that's a separate scenario from simply allowing libraries that >> depend on log4j-api to still work in Android. >> >> I do think that log4j-core could be useful on Android, but it'd really only >> be useful during development and not for end users. >> >>> On 9 July 2017 at 11:35, Mikael Ståldal <[email protected]> wrote: >>> >>> Assume that I am an Android developer. I don't know about Log4j, and I >>> don't care much about logging. I don't care about Java 9. >>> >>> In my Android app I want to use a Java library, which claims to support >>> Android. When I include a dependency to that library in my Gradle build, >>> the build breaks since the transitive dependency "log4j-api" has some >> Java >>> 9 classes in it. After mumbling about "damn this log4j crap", I try to >>> exclude it. Then I can build, but my app crash at runtime since the Java >>> library does some debug logging via Log4j API. >>> >>> To support Android means that the above does not happen. It means that >> the >>> build works and the app is not disrupted at runtime. It means that I can >>> live in bliss ignorance of Log4j. If all logging are just no-ops and >>> ignored on Android, that's OK for now. >>> >>> It is enough that log4j-api works on Android, log4j-core does not need to >>> work. I agree that most of log4j-core would be either impossible to get >> to >>> work, or not practically useful, on Android. >>> >>> >>> >>>> On 2017-07-09 16:31, Apache wrote: >>>> >>>> What does it mean to support android? You cannot log to a file system >> and >>>> many of our out of the box appender make no sense on a phone. >>>> >>>> What does having the API work on android mean without an implementation? >>>> We have never officially supported android and have just gotten our >> first >>>> Jura issue regarding it. >>>> >>>> I also keep hearing rumors that Google is going to drop Java in favor of >>>> a new language so I have suspicions they will never support Java 9. >>>> >>>> I don't want to go anywhere with android until I understand how it can >>>> be used. At that point I suspect we would create a jar that strips out >>>> stuff and call it Log4J-android. Dropping support for Java 9 should not >> be >>>> necessary to do that. >>>> >>>> Ralph >>>> >>>>> On Jul 9, 2017, at 5:56 AM, Mikael Ståldal <[email protected]> wrote: >>>>> >>>>> No matter what we think about it, many other Java libraries want to be >>>>> compatible with Android (even though that's not the main target). Some >> of >>>>> them also do logging, today often with Log4j 1, SLF4J or >> commons-logging. >>>>> >>>>> If we want them to migrate to Log4j 2 API, then it is important that >>>>> log4j-api does not cause issues on Android. If log4j-api breaks on >> Android, >>>>> that may be the reason for those libraries to not use it. >>>>> >>>>> I guess that Apache http-components is an example of this. >>>>> >>>>> Android support in log4j-core is less important (we can defer that to >>>>> 2.10 or possibly not do it al all). We don't need to be able to do >> fancy >>>>> logging on Android, but log4j-api should at least not break the build >> or >>>>> disrupt the regular operation of the app at runtime. >>>>> >>>>> If we don't do anything about it, then your effort on LOG4J2-1926 might >>>>> be wasted when the Java 9 stuff breaks Android builds. >>>>> >>>>> >>>>>> On 2017-07-09 14:15, Remko Popma wrote: >>>>>> Not sure I agree. Our interest in Android is a very recent thing. >> We've >>>>>> done some work with LOG4J2-1926 >>>>>> <https://issues.apache.org/jira/browse/LOG4J2-1926>, we are still >>>>>> discovering new work and I suspect we will keep discovering new issues >>>>>> as >>>>>> we start to take an in-depth look. If anything, let's make Android the >>>>>> "theme" for Log4j 2.10. >>>>>> Java 9 has been on the roadmap for a long time and is finally in a >> state >>>>>> where we can start asking for user feedback on it. >>>>>> I don't mind that Java 9 is still not officially released yet; it >> gives >>>>>> us >>>>>> some wiggle room in case we need to make changes. >>>>>> But I do like the version number symmetry: "Log4j offers Java 9 >> support >>>>>> from version 2.9". Call me a poet. :-) >>>>>> >>>>> >>>>> >>>> >>>> >>> >> >> >> -- >> Matt Sicker <[email protected]> >>
