ashvini sharma wrote:I couldn't find what the below section mean?
Well, I presume you understand the definitions
class Calendar implements Comparable<Calendar> { . . . }
class GregorianCalendar extends Calendar implements Comparable<GregorianCalendar> { . . . }
All it's saying is that you can't implement two
different versions of the same interface (don't forget,
Comparable<GregorianCalendar> is NOT a subclass of
Comparable<Calendar>).
In practise, it doesn't really make much difference, because you can always do something like:
class Calendar<T extends Calendar> implements Comparable<T> { . . . }
class GregorianCalendar extends Calendar<GregorianCalendar> { . . . }
HIH
Winston