Originally posted by April.Johnson:
From JLS 18.104.22.168: "Every interface is implicitly abstract."
From JLS 9.1.1: "The access modifier static pertains only to member interfaces."
So interfaces are implicitly abstract, not implicitly static.
Also you can have inner interfaces, referred to in JLS 9.1.1 as "member" or "nested" interfaces. (Also JLS 8.5 says: "A member interface is an interface whose declaration is directly enclosed in another class or interface declaration.")
Sandip is correct. From JLS 9.1.4: "All interface members are implicitly public."
As for why you'd use an inner interface, I haven't run across a situation that would warrant it, so I can't give you a real-world example.