java 三大特性--封装、继承和多态理解
封装

/** *  */package com.study.feature;/**    *  * @className ：Children   * @package : com.study.feature  * @Description ：测试    * @author：lgf    * @date ：2012 三月 12  14:55:15           * @version : 1.0 */public class Children extends Father{public void functionSecond(){System.out.println("Children functionSecond");}public static void main(String[] args) {Father c = new Children();c.functionOne();//Children functionSecond}}