Java 天地·Core Java·Lecture Notes·Unitt 07 - Inheritance and Interfaces

您的位置：寻梦网首页＞编程乐园＞Java天地＞Core Java＞Java Lecture Notes

Introduction

Content

Apply

Reflect

Extend

Content Index

Content Page # 12

Implementing an interface ?keyword 'implements'

The keyword 'implements' denotes inheritance from an interface, in the same way that 'extends' denotes inheritance from a class. A class can implement any number of interfaces. The class must provide an implementation for all the methods specified by the interface

Continuing the example above, if Compoment is a class, and KeyboardListener is an interface, then we specify that MyButton is a type of Component and a type of KeyboardListener as follows:

class MyButton extends Component implements KeyboardListener
{ void keyPressed()     {
    // instructions describing what to do when a key is
    // pressed
    } void keyReleased()     {
    // instructions describing what to do when a key is
    // released
    }
}

Note that the implementation of MyButton includes implementations of the methods ` keyPressed() ' and ` keyReleased()' as specified in the keyboardListener interface.

Back to top