Dashboard to check compatibility of Java modules (Java 9+)

[suztomo]

(ticket to track idea. Not decided to implement this yet)

Jeff found that we have multiple maven packages/modules providing the same package name which is not allowed in Java 9+ module system. Can BOM dashboard help to identify such problems across the Google Cloud libraries?

C.f. https://docs.oracle.com/javase/10/tools/jdeps.htm#JSWOR690

Split Packages

The Java Module System page 66 explains split package problem

• When compilation, exported packages are checked for split packages.
• When launch, split packages are checked regardless of exported or not.

Dependency Cycle

The Java Module System page 63 explains modules cannot have cyclic dependencies at launch.

Resolution Cyclic dependences will not be supported at this time. Jigsaw spec on CyclicDependencies

[suztomo]

Discussed with Elliotte, not doing this right now; no OKR and not many people use the new module system (yet).

[suztomo]

Discussed with Elliotte and David. To implement something very simple to check split packages.

[suztomo]

The result from an initial attempt (go/jdd-split-packages) revealed new issues such as com.google.longrunning and appengine-api-1.0-sdk-1.9.71.jar.

Branch is automatic_module_name.