Java interface definition (translated from Java tutorials)

From http://www.cnblogs.com/ggjucheng/archive/2012/12/04/2802120.html

English from http://docs.oracle.com/javase/tutorial/java/IandI/interfaceDef.html

An interface declaration consists of a modifier, a keyword interface, an interface name, a list of parent interfaces separated by commas (,) (if any), and an interface body. For example:

Public InterfaceGroupedinterfaceExtendsInterface1, interface2, interface3 {//Constant declarations//Base of natural logarithmsDoubleE = 2.718282;//Method signaturesVoidDosomething (IntI,DoubleX );IntDosomethingelse (string S );}
 

 

Public access indicates that the interface can be used by any package class. If you do not specify the public interface, your interface can only be accessed by the class of the same package.

An interface can inherit other interfaces, just like a class can inherit other classes. However, a class can inherit only one other class, and an interface can inherit any number of interfaces. The interface declaration contains all interfaces to be inherited by commas (,).

 

Interface body

The API provides a declaration that contains all methods. A method declaration of the interface is followed by a semicolon, but there is no braces, because the interface does not provide implementation for the method. All method declarations are implicitly public, so the public modifier can be ignored.

An interface can contain a constant declaration. The constant Declaration of the interface, which is implicitly public, static, final. Again, these modifiers can be ignored.