Inconsistencies in TreeSet Interface

[Martin Buchholz]

core-libs-dev is the right mailing list.

The documentation could be improved, but it's nuanced - consider using a
TreeSet with a Comparator that accepts null.

On Sat, Oct 13, 2018 at 7:26 AM, Kishor Gollapalliwar <
kishor.gollapalliwar at gmail.com> wrote:

> Hello Everyone,
>
> Introduction : I’m an enthusiast java developer. I’m a newbie in this
> group, hence please ignore my nuisance and guide me towards right
> direction.
>
> ## Problems Statement
>
> Treeset#add method documentations : “adds the specified element e to this
> set if the set contains no element e2 such that (e==null ? e2==null :
> e.equals(e2))”
>
> Inconsistencies:
>
> > If we try to add “null” value, it will throws NullPointerException, hence
> > e and e2 can not be null.
>
>
>
> > And e.compareTo(e2) ==0 || compare(e, e2)==0, it will not add to
> > collection.
>
>
> Request you to help me understand if behavior of Treeset#add method is as
> expected, and differ with set interface documentation. We may have to
> consider to update method documentations, if behavior is expected.
>
> For more details I have attached the sample java application.
>
> I’ve tested the behavior on Orack JDK 8u181 (64 bit) and Open JDK 8u181.
>
> Thanks & Regards,
> *Kishor Golapelliwar,*
> The ability to convert ideas to things is the secret to outward success.
>