Replacement for resource_jars in Bazel 5?

[Gunnar Wagenknecht]

Hi,

Bazel 5 dropped support for `resource_jars` on `java_library`. It's no longer possible to let Bazel package resources automatically in the jar. I came up with a possible alternative using `rules_pkg` to generate a jar and `java_import` to make it available as runtime dependency.

The problem I face is that this doesn't seem to work as expected. I do see the resources getting packaged properly. But the `java_binary` seems to be incapable of locating the resources.

An example change can be observed here:

https://github.com/salesforce/bazel-java-builder-template/commit/a1ee970db1a1ce907cae74725659f6a8067b39ba

To reproduce:

git clone g...@github.com:salesforce/bazel-java-builder-template.git

cd bazel-java-builder-template/examples/001-simple

bazel build :all

The produced java_binary is execute in a rule like this:

    ctx.actions.run(
        ..
        executable = ctx.executable._mybuilder,
        ...
    )

I can see the resource jars added to the run files manifest. However, if I look into the generated launcher script, I do not see the resource jar being added there to the CLASSPATH variable.

Is there anything else necessary to add the resource jar to the runtime deps?

-Gunnar

-- 
Gunnar Wagenknecht
gun...@wagenknecht.org, http://guw.io/

[Gunnar Wagenknecht]

Ok, switching from java_import to java_library fixes the problem.

https://github.com/salesforce/bazel-java-builder-template/commit/2fb1741ed2abc78d74453bdfbb6875222a1ab93c

Move this into https://github.com/bazelbuild/bazel/issues/15111

-Gunnar

-- 
Gunnar Wagenknecht
gun...@wagenknecht.org, http://guw.io/