Java Generics - implements and extends

Question

I am trying to write something like

public class A implements B {}

and

public abstract class M

        

Answer 1

When you have interfaces in generics, you still have to use the extends keyword.

In your case, if you know what T will be :

public class A implements B {}

If you don't and you simply have to implements B with a C type :

public class A implements B {}

For the second part, once you've defined I you can use it as is in your other generic types :

public abstract class M extends R implements Q {}

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Resources :

• www.angelikalanger.com - Java Generics FAQs
• Oracle.com - generics tutorial