It's explained in the TreeSet javadoc. On Tue, Jun 17, 2014 at 6:39 PM, David Holmes <david.holmes@oracle.com> wrote:

Moving your question to core-libs-dev, please drop build-dev from all future responses.

David

On 18/06/2014 10:56 AM, Su wrote:

...

May I ask why "contains" method of TreeSet uses the comparator to decide if two objects are equals, but not the equals method of the object?

Thank you.