实验三 内部类、常用类及异常类的用法 1.实验目的 (1)掌握 Java 中内部类的用法、异常类的用法 (2)掌握 Java 中 String 类常用方法、StringBuilder 类的用法; (3)掌握 System 类、Date 类、Calender 类、DateFormat 类、NumberFormat 类、Random 类与 BigInteger及 BigDecimal 类的用法; (4)掌握 Java 中正则表达式的基本用法; 2.实验内容 实验题 1 修改实验二实验题 4,声明一个局部变量 String text = "";然后通过循环把数组中的成员(有序)添加到 text 中,修改方法 JOptionPane.showMessageDialog();参数以显示 text。 Product 类 package cn.edu.nwsuaf.jp.p4.data; public abstract class Product implements Comparable{ @Override public String toString() { return getName()+"," +getPrice()+ "RMB"; } public int compareTo(Object o) { Product product = (Product)o; return new Integer(getPrice()).compareTo(product.getPrice()); } public abstract void output(Product p); public String getName() { return name; } public void setName(String name) { this.name = name; } public int getPrice() { return price; } public void setPrice(int price) { this.price = price; } private String name; private int price; public Product() { } public Product(String name, int price) { super(); this.name = name; this.price = price; } public static void main(String[] args) { // TODO Auto-generated method stub } } Mp3Player 类 package cn.edu.nwsuaf.jp.p4.data; public class Mp3Player extends Product{ public Mp3Player(String n,int p) { super(n,p); } public void output(Product p) { System.out.println(Mp3Player.class.toString()); } public static void main(String[] args) { } } Mobile 类 package cn.edu.nwsuaf.jp.p4.data; public class Mobile extends Product { public void output(Product p) { System.out.println(Mobile.class.toString()); } public Mobile(String n,int p) { super(n,p); } } Store 类 package cn.edu.nwsuaf.jp.p4; import cn.ed...