Allow filtering bean instances returned by ObjectProvider#stream()

[odrotbohm]

The implementations of ObjectProvider.stream() look up all bean names for the type referenced and subsequently look up the bean instance itself. This means that a call to ….stream() ultimately causes all bean instances to be initialized. It would be nice if there was a way to be selective about which of those instances I want to get by being able to filter on the bean name before instantiation.

My particular use case is to exclude beans of a particular type, so the filter being a BiPredicate<String, Class<?>> would prevent my code from having to obtain a reference to a BeanFactory to obtain the bean definition's type. That said, a simple stream(Predicate<String> beanNameFilter) would work as well.

[snicoll]

This seems to have some connection with #34203

[jhoeller]

Design-wise, filtering just by type is actually more attractive than filtering by bean name (since bean names have no conceptual exposure in the ObjectProvider API otherwise). @odrotbohm would a plain Predicate<Class<?>> do the job for you as well?

[odrotbohm]

It would, indeed.

[odrotbohm]

Would that need to be forward-ported to 7.0?