Marking optional member variable as NonNull

Question

One of the String member variables of my class is Optional. Does it makes sense to mark it with Lombok annotation @NonNull ?

I would like to ask the same question in case that member variable is Map instead of String. Will the answer change ?

Answer 1

Optional main point is to make fluent API. Field is not and should not be a part of API.

What is the difference for you between Optional<Object> obj and Object obj in fields?

Both of fields could be annotated with @NotNull. Annotating a field with @NotNull will give you the same result as annotating an Optional but without any extra calls like ifPresent(). If you want to use Optional to apply chaining operations to a field - you are using Optional in a wrong way. There in no reason to use Optional in field.

You can read more in openjdk mailing list optional discussion.

Having Optional enables to do fluent API mail.openjdk