It would be very convenient to be able to specify a "fallback" id generator to use when @GeneratedValue has no generator member, and the entity does not explicitly declare any @TableGenerator or @SequenceGenerator. This fallback could even be per-GenerationType.

One way would be via a property setting, so that, for example, you could set:

jakarta.persistence.generator.AUTO = myDefaultSequenceGenerator
jakarta.persistence.generator.SEQUENCE = myDefaultSequenceGenerator
jakarta.persistence.generator.TABLE = myDefaultTableGenerator

But actually the most natural solution would be to let you declare a @TableGenerator or @SequenceGenerator with no name at the package level. And then that generator would be used as the fallback for the whole package.

That's a great solution, but I believe @lukasj mentioned he has some problems with us using package-level annotations.