[hibernate-dev] BlobProxy, Reducing the amount of Proxies we rely on at runtime

[Sanne Grinovero]

I'm trying to understand if we could remove some of the usages of
`java.lang.reflect.Proxy`.

Clearly it's a long journey and maybe we will never be able to remove
them all, but I would at least want to try avoiding most of their neet
at runtime - limiting their usage at bootstrap/configuration or other
similar "one time" contexts.

We're all aware that these proxies have not been introduced lightly:
most are necessary or very useful; at least useful enough to prefer
having them to not having them; surely the tradeoffs have been
considered.

So what I'm trying to understand now is if all the tradeoffs made in
the past are still actual; some of the related code is > 10 years old;
I could use some help with evaluating what could be safely removed.

One example: org.hibernate.engine.jdbc.BlobProxy has the following comment:
"We use proxies here solely to avoid JDBC version incompatibilities."

Today we require Java8 as baseline, and the `java.sql.Blob` did not
change in any more recent JDK (I just thouroughly diff-ed the
JDK8,9,10,11,12 on this package using Gunnar's jdk-api-diff tool).

Would that be a reasonable candidate to replace the Proxy usage with a
plain implementation of the relevant interfaces? Clearly this implies
I'm betting that future JDKs will not break this again, still I'd
rather cleanup this usage today.

1 - Could I go ahead with that?

2 - Any more such cleanups come to mind?

Thanks,
Sanne