Preface: c ++ to learn a lot of java have forgotten
interface (interface) can be thought of as a "pure" abstract classes. It allows the creator to the provisions of the basic form of a class: method names, argument lists, and return types, but does not implement the method body
Interface also contains the basic data types of data members, but they are by default public, staticand final.
The method defined in the interface by default public, abstract.
Why member variables Java interface by default (public, static, final), members of the method (public, abstract) it?
The reason: the interface is a highly abstract template, member variables interface is part of the template, the interface implementation class must be a member of a total of these variables, modifiers member variables default to public, static, final. static so as to achieve this interface, this variable can be used directly.
If the non-static variable, multiple interface implementation class variable name may duplicate names phenomenon.
It represents a final modified variable constant can not be modified. It is a both a static field represents the final period can not be changed only occupy storage space. If the non-final variable, the interface implementation class variable's value may be modified, which is indistinguishable from the abstract class.
Since the interfaces play a role in standardization and regulation, so its member variables default modifier is static, final.