[hibernate-dev] HHH-9440 Support for Java 8: parameter names

Hello, I'd like to discuss issue HHH-9440. Basic idea behind this issue is that we try to and eliminate the requirement for no arg constructor on entities or at least weaken that requirement to specific cases. Construction from both the user code and the hibernate itself would go through user specified constructors. This would enable use cases like enforcing invariants in constructors, immutable entities and in the long run, maybe even support for value types coming in Java 10 that, at least for now, we know will be immutable and won't have a no arg constructor. By using parameter names and Java 8 API you can, for instance, map those parameter names to fields to find out column mappings and other information required for mapping arguments to parameters. A similar approach like this is used by jackson-databind with the jackson-module-parameter-names (this will soon be integrated into the jackson-databind itself). Another example, Spring also uses parameter names to map bean names to parameters in constructors. There are border cases like the one Steve mentioned in the issue: - use a library like Objenesis that enables you to construct classes without using the constructor - document that all entities that are to be proxied must have a no arg constructor What do you guys think?