buckpal VS jmolecules

We need rules to enforce boundaries, and they need to be treated like tests: when tests fail, one must fix them. Likewise, when one breaks a rule, one must fix it. ArchUnit is a tool to create and enforce rules. One configures the rules and verifies them as tests. Unfortunately, the configuration is time-consuming and must constantly be maintained to provide value. Here's a snippet for a sample application following the Hexagonal architecture principle:

Spring Modulith is the successor of Oliver Drotbohm's Moduliths project (with a trailing S). It uses both ArchUnit and jMolecules. At the time of this writing, it's experimental.

You could move towards modeling your code around DDD building blocks (like aggregates etc.) and declare those concepts in code explicitly using jMolecules types. There is a dedicated jMolecules Integrations ByteBuddy Plugin, that would then add the necessary boilerplate code and default mappings required by the expressed concept. This makes the code shown here a fully working JPA model. You can argue that the lack of JPA oddities is odd itself in the first place but I like the idea of expressing the architectural concept explicitly and the technology integration completely flowing from that.