File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes Beginning Java and the fly likes abstract interface? Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of Android Security Essentials Live Lessons this week in the Android forum!
JavaRanch » Java Forums » Java » Beginning Java
Bookmark "abstract interface?" Watch "abstract interface?" New topic

abstract interface?

Bala Krishna
Ranch Hand

Joined: Jan 26, 2001
Posts: 95
I know what abstract classes and what interfaces are. But, whey would we need to declare an interface as 'abstract'? For ex: (FilterChain interface of javax.servlet.http). I do not see any necessity of declaring an interface as an abstract. Am I missing something? Can some one please shed some light?
Jacky Chow
Ranch Hand

Joined: Sep 01, 2002
Posts: 63
interfaces are implicitly abstract, that means use or not use the abstract key word with interface are the same.

Bala Krishna
Ranch Hand

Joined: Jan 26, 2001
Posts: 95
Exactly my point. Why use the word 'abstract' when it's not needed? It's like saying JSP page.
Wilfried LAURENT
Ranch Hand

Joined: Jul 13, 2001
Posts: 269
That's what the JLS says in abstract Interfaces
"Every interface is implicitly abstract. This modifier is obsolete and should not be used in new Java programs. "
Bala Krishna
Ranch Hand

Joined: Jan 26, 2001
Posts: 95
Thanks for clarifying that Wilfried. So, what does this mean? That the people who wrote the lattest Servlet API would did NOT read the JLS?
And I thought I was the only one who tried to learn Java without reading the JLS. hehe!
I agree. Here's the link:
subject: abstract interface?
Similar Threads
Abstract interface!!!????
Question on Interface
About interface and abstract classes
abstract interface
Exact Use of Abstract Class And Interface