interface in Java

Specifiers in Java.

Variable in interfaces have some implicit Access Specifiers:

package indoscopy;
public interface Foo {
int k = 4;        /* is equivalent final int k = 4;
  * public int k = 4;
  *static int k = 4;

  *Interfaces can have constants,
  *which are always implicitly public, static, and final.
  *Interface constant declarations of public, static, and final
  *are optional in any combination.
  */
}