Use @EnableTransactionManagement(proxyTargetClass = true)

[philwebb]

We should use @EnableTransactionManagement(proxyTargetClass = true) to prevent nasty proxy issues when people aren't using interfaces.

[snicoll]

I don't think that's the only one that's involved here. @EnableCaching is in the same camps (and probably others). Do we really want to do that switch unconditionally? Maybe we should improve the error message instead?

[philwebb]

Switching it on by default shouldn't have any side-effects, especially since cglib is repackaged as part of Spring anyway.

[odrotbohm]

Unfortunately it has :(. See SPR-14322 for details.

[philwebb]

@olivergierke Looks like SPR-14322 isn't going to be fixed in 4.x. I'm still tempted to leave proxyTargetClass as the new default. Do you think we need to reconsider that decision?

[vinisxs]

I have a web project that uses Spring and needed to make a batch module for it so I decided to go with Spring Boot and reused my services module from the bigger project. The services module has a ton of final methods and does not go well with cglib and it took me 2 days to understand and fix why cglib proxies where being used despite the fact that all services implemented interfaces.

I also tried changing spring.aop.proxy-target-class in properties but it was ignored (#8434).

It seems to me that changing the default was a bad call. It breaks a well known behavior of Spring.