↗️ This README only covers one section of the demo. The master branch contains more information.

Getting a dependency cycle past the compiler requires a little bit of effort:

• build all modules as usual (i.e. without any cycle)
• add dependency from monitor.persistence to monitor.rest and rebuild it against the usual modules
• add dependency from monitor.rest to monitor.persistence and rebuild it against the usual modules
• replace usual versions of monitor.persistence and monitor.rest with new ones

Because each half of the cycle was built against a version of the depended module that did not have the dependency back, the compiler never saw the cycle. Only when both versions come together is there actually a cycle.

(Only in compile.sh, not with Maven.)

The runtime catches it:

Error occurred during initialization of boot layer
java.lang.module.ResolutionException:
Cycle detected: monitor.persistence -> monitor.rest -> monitor.persistence