Provide a multi-release jar?

[laeubi]

Is your feature request related to a problem? Please describe.
Currently there are two jar build, one for java 8 and one for java 11

Describe the solution you'd like
JEP 238 defines a way to build a single jar that can contain code for java 8 and any version 9+ in the same jar.

Additional context
Having only one dependency will likely simplify build (only one pom) and usage (java 11 code is automatically used when running on a suitable vm).

[filip26]

Hi @laeubi, thank you for sharing JEP 238. I've been looking for something like that for a long time.

[laeubi]

The maven setup is a bit cumbersome, but if you like you can find an example here: https://github.com/ClickHouse/clickhouse-jdbc/blob/f285b73d45597e29cf36dff4daf4cb4f9f53453a/pom.xml#L498-L532

[filip26]

thanks, that looks promising, I see it uses jdkToolchain. I wonder how to build it using Github Actions.

[filip26]

#166

[laeubi]

I wonder how to build it using Github Actions.

You can vote for actions/setup-java#276

You can add a static one e.g. like this
https://github.com/eclipse-platform/eclipse.platform/blob/master/.github/toolchains.xml

and pass it to the maven build:
https://github.com/eclipse-platform/eclipse.platform/blob/4d2af8c7770d66a025f349513b5fe9f379a2630b/.github/workflows/build.yml#L31

but I have also seen generate it on the fly...

[laeubi]

@filip26 is there any schedule for this already? Once this is done I'd like to propose a patch on this to add OSGi meta-infos, so would be nice to hear if it makes sense to wait for this or better do the work twice in the old infrastructure.

[filip26]

Hi @laeubi ,
I'm sorry, but I cannot set a date. Titanium is an open-source project and no one gets paid to work on it., It could be a week or a few months.

[laeubi]

Alright, let me know if I can help with anything.

[filip26]

Well, I'm happy to accept any PR that is in benefit of the library users ;)

[filip26]

add a resource Multi-release JARs - Good or bad idea?

[laeubi]

Well that is more than five years ago now and I see MJARS in the wild (e.g. gson)... beside that its not the responsibility of a library to overcome possibly limitations of tools (gradle?), but for sure it is your choice in the end :-)

[filip26]

thank you for the reaction. The only motivation to provide JRE8 build is Android development for which Gradle is preferred over Maven. Do you have an experience with MJARS on Android?

[laeubi]

No, but as MJARs (from Java/Android POV) are just jars with a few extra bytes I won't expect anything worse here and any Java ) compliant JVM should support MJARs at the runtime.

[filip26]

closed due inactivity, feel free to re-open with new information.