jar --verify operation mode checking mrjar validity

Jaikiran Pai jaikiran at apache.org
Mon Dec 3 06:19:55 UTC 2018

On 02/12/18 3:43 PM, Alan Bateman wrote:
> On 01/12/2018 08:45, Christian Stein wrote:
>> Hi,
>> jar --create (and --update) perform type API validation checks when
>> used in
>> combination with --release option. This detects invalid "version
>> overlays"
>> at package time, where the API doesn't match a previous one.
>> Having a jar --verify mode that performs the same checks consuming an
>> already existing jar file would be useful as most "3rd-party packaging
>> tools" don't perform those checks.
>> A possible work-around could be to explode an existing jar and
>> re-create it
>> using jar --create...
> I think it would be useful to create a list of the popular tools and
> plugins in the eco system that create or update JAR files and see what
> their current capabilities are. The addition of modules and MR JARs
> have extended the JAR format quite a bit in recent years and it's not
> clear if the eco system has caught up,

FWIW - We (Apache Ant) haven't yet caught up with many of these
changes/enhancements, both in what the Java tools (like jar, jmod
etc...) have introduced[1][2][3], nor in runtime aspects like
multi-release jars[4]. It's going to take us a while to catch up with
these current new enhancements.

[1] https://bz.apache.org/bugzilla/show_bug.cgi?id=62789
[2] https://www.mail-archive.com/user@ant.apache.org/msg42796.html
[3] https://www.mail-archive.com/dev@ant.apache.org/msg47740.html
[4] https://bz.apache.org/bugzilla/show_bug.cgi?id=62952


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