1.4Tinking in java--适配器

适配器设计模式：

抽象类实现接口，再继承抽象类，方法之覆盖需要用到的

package java.awt.event;public abstract class KeyAdapter implements KeyListener {    /**     * Invoked when a key has been typed.     * This event occurs when a key press is followed by a key release.     */    public void keyTyped(KeyEvent e) {}    /**     * Invoked when a key has been pressed.     */    public void keyPressed(KeyEvent e) {}    /**     * Invoked when a key has been released.     */    public void keyReleased(KeyEvent e) {}}