Why does the generic bound "E implements I" result in a compiler error?

Question

Why does this compile:

class MaxMin<E extends Comparable<E>>
{
   E max=null;
   E min=null;
}

...but this doesn't?

class MaxMin<E implements Comparable<E>>
{
   E max=null;
   E min=null;
}

Answer 1

Generic type bounds only specify extends and super.

Quoting the Java Generics Tutorial(emphasis mine)

To declare a bounded type parameter, list the type parameter's name, followed by the extends keyword, followed by its upper bound, which in this example is Number. Note that, in this context, extends is used in a general sense to mean either "extends" (as in classes) or "implements" (as in interfaces)