I believe this is a by-product of the protobuf changes. Google Protobuf returns an empty string if you're trying to access an optional field with no default value associated with it. This can lead to subtle bugs..
Users of `Message` API should always check `hasKey()` before trying to do `getKey()`. (A better API would have been to return an `Optional<String>`). In any case, I'd rather not change the behavior of this right now, but leave it in the same form as 2.7 and earlier versions. -- Matteo Merli <mme...@apache.org> On Tue, May 18, 2021 at 12:50 AM Enrico Olivelli <eolive...@gmail.com> wrote: > > Hello, > I have found this behaviour in the Java Client while switching from 2.7 to > 2.8. > > Short version of the story: > - on 2.7.2 a null key is received as an empty key > - on 2.8.0 a null key is received as a null key > > The behaviour of 2.8 is better, because it is what you expect. > > But if you migrate an application from 2.7.2 to 2.8 you can start to > see Nulls instead of empty strings and this will lead to unpredictable > behaviour and possibly NullPointerExceptions. > > We can accept the new behaviour but I would like to check if the > community is aware of this and this is acceptable. > > This is the issue, with a reproducer > https://github.com/apache/pulsar/issues/10625 > > Enrico
