Well, if they changed the package names so there is no conflict then I guess we will have to have both versions.
Ralph On May 16, 2013, at 11:07 AM, Nick Williams wrote: > It's not just the groupId/artifactId that changed between Jackson 1 and > Jackson 2. It's the Java package, too. Simply excluding Flume's dependency on > 1.x and introducing a dependency on 2.x doesn't work. Flume classes literally > don't load due to NoClassDefFound errors. > > N > > On May 16, 2013, at 1:04 PM, Ralph Goers wrote: > >> The master log4j pom.xml should have a version for jackson in the dependency >> management section. That version should replace any transitive dependencies. >> However, if the groupId has changed then that doesn't work. You would have >> to add the Jackson 2 dependencies to flume-ng's pom.xml and exclude the old >> artifact/groupId. >> >> Note that required transitive dependencies are never obvious just by looking >> at a pom. >> >> Ralph >> >> >> On May 16, 2013, at 10:17 AM, Nick Williams wrote: >> >>> So this is all kinds of fun... >>> >>> log4j-core depends on: >>> ....jackson 1.9.11 (optional) >>> log4j-flume-ng depends on: >>> ....flume-ng-sdk 1.3.1 depends on: >>> ........avro 1.7.2 depends on: >>> ............jackson 1.8.8 >>> flume-embedded (sample) depends on: >>> ....flume-ng-sdk 1.3.1 depends on: >>> ........avro 1.7.2 depends on: >>> ............jackson 1.8.8 >>> ....flume-ng-node 1.3.1 depends on: >>> ........jackson 1.9.3 >>> >>> So, we already had three different versions of Jackson in the build: 1.8.8, >>> 1.9.3, and 1.9.11 ... yuck! >>> >>> I took the following steps: >>> >>> 1) I upgraded log4j-core's dependency from 1.9.11 to 2.2.1 without any >>> negative consequences. Everything compiled and all the tests passed. At >>> this point the dependencies were now 1.8.8, 1.9.3, and 2.2.1. >>> 2) I used dependency exclusions to exclude 1.8.8 and got it down to just >>> 1.9.3 and 2.2.1. Everything compiled and all the tests passed. >>> 3) I tried to eliminate 1.9.3 through a further dependency exclusion, but >>> log4j-flume-ng classes didn't load anymore. This indicated that Jackson is >>> NOT an optional dependency of log4j-flume-ng, but instead is a mandatory >>> dependency, which wasn't obvious the way it was set up. >>> 4) I kept the 1.9.3 dependency exclusion but added a mandatory 1.9.11 >>> /runtime/ dependency for log4j-flume-ng. Now everything compiles and all >>> tests pass again, and the Jackson dependencies are limited to the latest >>> minor.patch versions of each major version: 1.9.11 (log4j-flume-ng only, >>> runtime) and 2.2.1 (log4j-core only, compile). >>> >>> Ralph said below "I have no problem upgrading to 2.x so long as it works >>> for both the JSON configuration and Flume." It doesn't work with Flume; >>> Flume requires 1.x. So as a next step we can either: >>> >>> 1) Revert my changes to configuration so that it relies on Jackson 1.9.11 >>> as well and not on 2.2.1. >>> 2) Apply my earlier suggestion that we support both 1.9.11 /and/ 2.2.1 or >>> configuration. >>> 3) Stick with what we have: 1.9.11 for Flume, 2.2.1 for JSON configuration, >>> and no more dependency on 1.8.8. >>> >>> Nick >>> >>> On May 15, 2013, at 7:33 PM, Ralph Goers wrote: >>> >>>> I wrote the JSON support just after the ApacheCon in Vancouver, which I >>>> believe was in 2011. If 2.x was available then it was brand new and the >>>> documentation was slim. I have no problem upgrading to 2.x so long as it >>>> works for both the JSON configuration and Flume (I don't think Flume >>>> actually uses JSON but Avro probably does). Like you, I would prefer not >>>> to have two versions of Jackson in out build. >>>> >>>> Ralph >>>> >>>> >>>> On May 15, 2013, at 11:16 AM, Gary Gregory wrote: >>>> >>>>> I would only support the current version: 2.x. >>>>> >>>>> Gary >>>>> >>>>> >>>>> On Wed, May 15, 2013 at 2:00 PM, Nick Williams >>>>> <nicho...@nicholaswilliams.net> wrote: >>>>> Guys, >>>>> >>>>> Background: Since I'm the lead developer on a Jackson Mapper module >>>>> (https://github.com/FasterXML/jackson-datatype-jsr310), I'm actively >>>>> involved on their development mailing list. >>>>> >>>>> Jackson 1.9 is, well, old. Specifically, 1.9.0 is two years old. 1.9 is >>>>> the last minor version of the 1.x family. There will continue to be bug >>>>> fixe releases—for now—about every 4-6 months. The last patch release was >>>>> in January. >>>>> >>>>> Jackson 2.x is the current version with rapid release periods. 2.0 Is >>>>> about a year old, 2.1 was released in October and 2.2 was released last >>>>> month. Only major bugs will be fixed in 1.9.x. Minor bug fixes and all >>>>> new features will go in 2.x. >>>>> >>>>> Jackson 1.x and 2.x use different Java packages. This has both advantages >>>>> and disadvantages. One advantage is that frameworks and libraries, like >>>>> Spring Framework, can easily support both versions because they can >>>>> coexist on the same class path during compilation and testing. One >>>>> disadvantage is that if some library is using 1.x and some other library >>>>> is using 2.x and you create an application that depends on both >>>>> libraries, you'll have to pull BOTH versions of Jackson on to your class >>>>> path. Ugh. >>>>> >>>>> Log4j 2 is "brand new" (it's not even released yet). Typically, I would >>>>> argue that new projects should not use old versions of their >>>>> dependencies. In Log4j 2's case, I tend to lean the same direction. It >>>>> doesn't seem wise to tie ourselves to Jackson 1.x so late in its life >>>>> when Jackson 2.x is already mature and Log4j 2 isn't even released yet. >>>>> As a Java 8, Spring 4, Jackson 2 user, I know I wouldn't love having to >>>>> also have Jackson 1 on my class path (if I were using JSON configuration). >>>>> >>>>> I would suggest that we should either support both or we should only >>>>> support 2.x, but only supporting 1.x feels wrong to me. >>>>> >>>>> Supporting both wouldn't be a major challenge. The way Spring does it is >>>>> to have two Jackson* classes and Jackson2* classes with identical APIs. >>>>> Depending on which version you are already using, you use the appropriate >>>>> class. In this case, I would approach it like this: >>>>> >>>>> - Rename JSONConfiguration to Jackson1JSONConfiguration, and (using >>>>> CheckStyle's import control) ensure that only this class imports Jackson >>>>> 1.x >>>>> - Create a similar class named Jackson2JSONConfiguration, and ensure that >>>>> only this class imports Jackson 2.x >>>>> - Alter JSONConfigurationFactory to detect which version is on the class >>>>> path and return the appropriate JSON configuration, preferring 2.x if >>>>> both are on the class path >>>>> >>>>> Thoughts? >>>>> --------------------------------------------------------------------- >>>>> To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org >>>>> For additional commands, e-mail: log4j-dev-h...@logging.apache.org >>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org >>>>> Java Persistence with Hibernate, Second Edition >>>>> JUnit in Action, Second Edition >>>>> Spring Batch in Action >>>>> Blog: http://garygregory.wordpress.com >>>>> Home: http://garygregory.com/ >>>>> Tweet! http://twitter.com/GaryGregory >>>> >>> >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org >>> For additional commands, e-mail: log4j-dev-h...@logging.apache.org >>> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org >> For additional commands, e-mail: log4j-dev-h...@logging.apache.org >> > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org > For additional commands, e-mail: log4j-dev-h...@logging.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org For additional commands, e-mail: log4j-dev-h...@logging.apache.org
