Can SerialVersionUid be any number or should it be generated by the compiler?

Question

If I write serialversionUid for my class, as 1234 say, and I know that no other class in my program uses this, is that fine or do I always need to use the uid generated by the compiler?

Answer 1

serialVersionUID can be long, which provides a unique signature for your object for serialization and deserialization. I don’t think it should even be unique. This means that the serializer knows that it is the same Foo.class, even after you change the structure of the class. Usually I use -1L for value.

Answer 2

It can be any number, and he only needs to submit a version of this class. This does not have to be unique.