On Sun, Nov 24, 2013 at 1:24 PM, Cédric Beust ♔ <ced...@beust.com> wrote:
> I would be totally on board with constructor injection if finalguaranteed > structural immutability, but all it does is guarantee reference > immutability (“this field is only assigned once”), ... > That's *not* all it does. Final fields provide additional safety guarantees even in the presence of data races involving a reference to the containing object: As long as that reference isn't leaked during construction, the final fields *and everything reachable through them* are guaranteed to be properly constructed. The same is not true for non-final fields. So if an object has a field *map* that is assigned to a HashMap built during construction, say, and you accidentally pass a reference to that object, *obj**,* to another thread (after construction) via a data race (no *happens-before* edge), then *obj.map* in the new thread is guaranteed to see the properly constructed HashMap only if the *map* field is final. It might seem like a marginal advantage, but for some folks this additional guarantee tips the scales in favor of final. But I think the other argument that Tim (other Tim!) advanced is more important: In addition to providing those guarantees, final clearly declares your intent. --tim -- You received this message because you are subscribed to the Google Groups "google-guice" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-guice+unsubscr...@googlegroups.com. To post to this group, send email to google-guice@googlegroups.com. Visit this group at http://groups.google.com/group/google-guice. For more options, visit https://groups.google.com/groups/opt_out.
